Forward-Looking Statements This communication contains "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995, including, but not limited to, statements regarding: the exp

resTORbio and Adicet Bio July 28, 2020

Forward-Looking Statements This

communication contains "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995, including, but not limited to, statements regarding: the expected structure, timing and completion of the

proposed merger transaction, future product development plans and projected timelines for the initiation and completion of preclinical and clinical trials; the potential for the results of ongoing preclinical or clinical trials and the efficacy of

either party's drug candidates; the potential market opportunities and value of drug candidates; future product development and regulatory strategies, including with respect to specific indications; the combined company's future

financial performance, results of operations or sufficiency of capital resources to fund operating requirements; future NASDAQ listing; expectations regarding the combined company's focus, operations, resources and development plan;

expectations regarding synergies resulting from the proposed merger transaction; the executive and board structure of the combined company; expectations of the potential impact of the COVID-19 pandemic on resTORbio, Inc.'s

("resTORbio"), Adicet Bio, Inc.'s ("Adicet") and the combined company's strategy and future operations, including ability to access capital or obtain additional financing, and ability to conduct, and the timing

of, clinical trials; and the potential payment of proceeds pursuant to the CVR Agreement by and between resTORbio, the Holders' Representative (as defined therein) and the Rights Agent (as defined therein) (as defined in the Agreement and Plan of

Merger, dated April 28, 2020, by and among resTORbio, Adicet and Project Oasis Merger Sub, Inc.). The use of words such as, but not limited to, "believe," "expect," "estimate," "project,"

"intend," "future," "potential," "continue," "may," "might," "plan," "will," "should," "seek," "anticipate," or

"could" and other similar words or expressions are intended to identify forward-looking statements. Forward-looking statements are neither historical facts nor assurances of future performance. Instead, they are based on

resTORbio's current beliefs, expectations and assumptions regarding the future of resTORbio's and Adicet's business, future plans and strategies, clinical results and other future conditions. New risks and uncertainties may emerge

from time to time, and it is not possible to predict all risks and uncertainties. No representations or warranties (expressed or implied) are made about the accuracy of any such forward-looking statements. There can be no assurance that the parties

will be able to complete the proposed merger transaction on the anticipated terms, or at all. Such forward-looking statements are subject to a number of material risks and uncertainties including but not limited to: (i) risks associated with

resTORbio's ability to obtain the stockholder approval required to consummate the proposed merger transaction and the timing of the closing of the proposed merger transaction, including the risks that a condition to closing would not be

satisfied within the expected timeframe or at all or that the closing of the proposed merger transaction will not occur; (ii) the outcome of any legal proceedings that may be instituted against the parties and others related to the merger agreement;

(iii) unanticipated difficulties or expenditures relating to the proposed merger transaction, the response of business partners and competitors to the announcement of the proposed merger transaction, and/or potential difficulties in employee

retention as a result of the announcement and pendency of the proposed merger transaction; (iv) the length of time necessary to consummate the proposed merger transaction may be longer than anticipated; (v) resTORbio's continued listing on the

NASDAQ Global Market until closing of the proposed merger transaction; (vi) the combined company's listing on the NASDAQ Global Market after closing of the proposed merger transaction; (vii) the adequacy of the combined company's capital

to support its future operations and its ability to successfully initiate and complete clinical trials; (viii) the nature, strategy and focus of the combined company; (ix) the difficulty in predicting the time and cost of development of

resTORbio's and Adicet's product candidates; (x) the executive management and board structure of the combined company; (xi) the risk that any potential payment of proceeds pursuant to the CVR Agreement may not be distributed at all or

result in any value to resTORbio's stockholders; (xii) Adicet's plans to develop and commercialize its product candidates, including ADI-001; (xiii) the timing of initiation of Adicet's planned clinical trials; (xiv) the timing of

the availability of data from Adicet's clinical trials; (xv) the timing of any planned investigational new drug application or new drug application; (xvi) Adicet's plans to research, develop and commercialize its current and future

product candidates; (xvii) Adicet's ability to enter into new collaborations, and to fulfill its obligations under any such collaboration agreements; (xviii) the clinical utility, potential benefits and market acceptance of Adicet's

product candidates; (xix) Adicet's commercialization, marketing and manufacturing capabilities and strategy; (xx) Adicet's ability to identify additional products or product candidates with significant commercial potential; (xxi)

developments and projections relating to Adicet's competitors and its industry; (xxii) the impact of government laws and regulations; (xxiii) Adicet's ability to protect its intellectual property position; (xxiv) Adicet's estimates

regarding future revenue, expenses, capital requirements and need for additional financing following the proposed merger transaction; and (xxv) those risks detailed in resTORbio's preliminary proxy statement/prospectus/information statement

filed with the U.S. Securities and Exchange Commission (the "SEC") on June 23, 2020 (and when available, resTORbio's definitive proxy statement/prospectus/information statement), as well as discussions of potential risks,

uncertainties, and other important factors in resTORbio's subsequent filings with the SEC. Any forward-looking statement speaks only as of the date on which it was made. None of resTORbio, Adicet, nor their affiliates, advisors or

representatives, undertake any obligation to publicly update or revise any forward-looking statement, whether as result of new information, future events or otherwise, except as required by law. Industry and Market Information Information regarding

market share, market position and industry data pertaining to Adicet's, resTORbio's and the combined company's business contained in this presentation consists of estimates based on data and reports compiled by industry

professional organizations and analysts and Adicet's and resTORbio's knowledge of their industry. Although Adicet and resTORbio believe the industry and market data to be reliable, this information could prove to be inaccurate. You

should carefully consider the inherent risks and uncertainties associated with the market and other industry data contained in this presentation. Forward-looking information obtained from third-party sources is subject to the same qualifications and

the additional uncertainties as the other forward-looking statements in this presentation.

Regulation M-A Legend Important

Additional Information About the Proposed Merger and Where to Find It This communication relates to the proposed merger transaction involving resTORbio, Inc. ("resTORbio") and Adicet Bio, Inc. ("Adicet") and may be deemed to

be solicitation material in respect of the proposed merger transaction. In connection with the proposed merger transaction, resTORbio has filed with the U.S. Securities and Exchange Commission (the "SEC") a registration statement on Form

S-4 (the "Form S-4") that contains a preliminary proxy statement/prospectus/information statement. The Form S-4 has not yet become effective. After the Form S-4 is declared effective, a definitive proxy statement/prospectus/information

statement will be mailed to the stockholders of resTORbio and Adicet. This communication is not a substitute for the Form S-4, the definitive proxy statement/prospectus/information statement or for any other document that resTORbio may file with the

SEC and or send to resTORbio's stockholders in connection with the proposed merger transaction. BEFORE MAKING ANY VOTING DECISION, INVESTORS AND SECURITY HOLDERS OF RESTORBIO ARE URGED TO READ THE FORM S-4, THE DEFINITIVE PROXY

STATEMENT/PROSPECTUS/INFORMATION STATEMENT AND OTHER DOCUMENTS FILED WITH THE SEC CAREFULLY AND IN THEIR ENTIRETY WHEN THEY BECOME AVAILABLE BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION ABOUT RESTORBIO, THE PROPOSED MERGER TRANSACTION AND RELATED

MATTERS. Investors and security holders will be able to obtain free copies of the Form S-4, the definitive proxy statement/prospectus/information statement and other documents filed by resTORbio with the SEC through the website maintained by the SEC

at http://www.sec.gov. Copies of the documents filed by resTORbio with the SEC will also be available free of charge on resTORbio's website at www.restorbio.com, or by contacting resTORbio's Investor Relations at 212-362-1200.

Participants in the Solicitation resTORbio, Adicet and their respective directors and certain of their executive officers may be considered participants in the solicitation of proxies from resTORbio's stockholders with respect to the proposed

merger transaction under the rules of the SEC. Information about the directors and executive officers of resTORbio is set forth in the preliminary proxy statement/prospectus/information statement, which was filed with the SEC on June 23, 2020, and

in subsequent documents filed with the SEC. Additional information regarding the persons who may be deemed participants in the proxy solicitations and a description of their direct and indirect interests, by security holdings or otherwise, will also

be included in the Form S-4, the definitive proxy statement/prospectus/information statement and other relevant materials to be filed with the SEC when they become available. You may obtain free copies of this document as described above. No Offer

or Solicitation This communication does not constitute an offer to sell or the solicitation of an offer to buy any securities nor a solicitation of any vote or approval with respect to the proposed transaction or otherwise. No offering of securities

shall be made except by means of a prospectus meeting the requirements of Section 10 of the U.S. Securities Act of 1933, as amended, and otherwise in accordance with applicable law.

Presence of T cells in

tumors was observed to strongly correlate with improved overall prognosis, improved survival and progression free survival Express T-cell and NK cell receptors, facilitating adaptive and innate anti-tumor immune responses with more limited ability

for tumor escape Inherent propensity to home to tissues and malignancies Allogeneic and off-the-shelf with potential to re-dose patients and no expected GvHD Potential for outpatient administration cGMP-compliant manufacturing from healthy donors

Proprietary T Cell Receptor-Like (TCR-L) monoclonal antibodies platform targeting intracellular targets presented on MHC complexes Adicet Engineered Gamma-Delta ( ) CAR-T Platform CAR: Chimeric Antigen Receptors; NK: Natural Killer; GvHD:

Graft Versus Host Disease; MHC: Major Histocompatibility Complex; NKG2D: NK Group 2D; NCR=Natural Cytotoxicity Receptors; DNAM-1: DNAX accessory molecule-1

Adicet Bio/resTORbio Merger Close

expected 2H 2020 $141 million pro forma cash, cash equivalent and marketable securities March 31, 2020 Post-merger entity expected to be well capitalized into 2022 Established partnership with Regeneron Multiple near-term milestones New company

expected to be listed on NASDAQ (ticker: ACET) On a pro forma basis, current Adicet and resTORbio equityholders are expected to own approximately 75% and 25% of the combined company, respectively

Adicet Bio Post Merger Leadership Team

Chen Schor President and CEO Stewart Abbot, PhD Chief Scientific and Operating Officer Carrie Krehlik Chief Human Resource Officer Lloyd Klickstein, MD, PhD Chief Innovation Officer Francesco Galimi, MD, PhD Chief Medical Officer

Improving Cancer Immunotherapy Presence

of T Cells Observed to Strongly Correlate with Positive Clinical Outcomes Meraviglia et al. 2017 Improved Disease Free Progression Colorectal Cancer T cell hi T cell lo T cell lo / IFN lo

Pan-Cancer: Improved Overall Prognosis Gentles et al. 2015 Godder et al. 2007 Post-HSCT Improved Survival T cell hi T cell lo Overall Survival HSCT: Hematopoietic Stem Cell Transplantation

NH: Non-Hodgkin's ; HCC:

hepatocellular carcinoma Building a Broad Pipeline of First in Class CAR T Cell Therapy Program Target Indication Discovery Preclinical IND Phase 1 Phase 2 ADI-001 CD20 NH Lymphoma ADI-002 GPC3 HCC ADI-00x Undisclosed Solid

Tumors ADI-00x Multiple Solid and Heme

Multiple Expected Near-Term Milestones

File IND for ADI-001 CD20 gamma-delta CAR-T Phase 1 clinical study in non-Hodgkin's lymphoma ADI-001 expansion in DLBCL and/or MCL Phase 1 in HCC and other solid tumors Expand pipeline in oncology and other diseases File IND for ADI-002 GPC3

gamma-delta CAR-T DLBCL: Diffuse Large B Cell Lymphoma; MCL: Mantle Cell Lymphoma

Key Anticipated Advantages of

Adicet's Allogeneic 1 T Cell Platform Confidential use only Innate and adaptive immunity imparted by TCR and NK receptors May mitigate tumor relapse MHC-independent tumor targeting Off-the-shelf product, potential to re-dose No /

low potential to cause GvHD Potent IFN production Potential for integrin-mediated trafficking to solid tumors Scalable manufacturing from healthy donors Not compromised by patient's immune system dysfunction MICA / B B7-H6, etc. MHC-

unrestricted antigens CD20 Nectin-2, etc. Galectin-3, NKp44L, etc.

Platform Anticipated Advantages: Engineered to address activity, tumor homing, safety, and COGs limitations Allogeneic CAR T Cells Allogeneic CAR NK Cells Allogeneic CAR T Cells Activity Innate anti-tumor response Adaptive

anti-tumor response Active tumor homing Predominantly activating receptor expression (Limited number) (Balance with inactivating) Preclinical persistence by repeat tumor challenge Prognostic value of tumor infiltration Safety Low GvHD risk (Requires

TCR deletion) Low risk of cytokine release syndrome grade 3 risk COGS No gene editing required (May affect efficacy) Scalable manufacturing Limited without exhaustion

Large-Scale Manufacture of

T Cells Proprietary AM3579 activating antibody to expand 1 T cells, Proprietary Vectors, Proprietary Scalable Process

Anticipated Consistent Proprietary

Large-Scale Expansion Fully cGMP-compliant manufacturing process Available on demand for single or repeated dosing Consistent clinical-scale manufacture >6,000 fold expansion of V 1 T cells at clinical scale Highly cost efficient: Up to

1,000 doses / batch Data above are from full-scale clinical productions conducted by Adicet and cGMP-compliant contract manufacturing organization

Effectively Control Aggressive Lymphoma Tumors in Mice Untreated animals succumb to highly aggressive tumors within 3 weeks 2nd generation (employing two co-stimulation domains) CD20 CAR T cells effectively control multiple

disseminated (iv) and localized (sc) tumors T cell treatment initiated* when tumor volume 200mm3 Intravenous Raji Tumor Growth * Subcutaneous Raji Tumor Growth * -5 0 5 10 15 20 25 30 35 0 1 10 10 2 10 10 3 10 10

4 10 10 5 10 10 6 10 10 7 10 10 M e a n T o t a l F l u x ( p / s ) + / - S E M Intravenous Granta Tumor Growth * Subcutaneous Mino Tumor Growth * internal Adicet study

Effectively Control Repeat Lymphoma Challenges and Demonstrate Functional Persistence for 100 Days Repeat tumor challenge is one of the most stringent tests of anti-tumor activity CD20 CAR T cell treatment initiated* when tumor volume

200mm3 Excellent tumor control in all animals at day 55 Secondary tumor challenge at day 60 CD20 CAR T demonstrate functional persistence and control tumor growth to 100 days * internal Adicet study In Vivo

Subcutaneous Raji Tumor Killing 1 Tumor Challenge 2 Tumor Challenge Mean Tumor Volume (mm3)+/- SEM

Proliferate in Response to Activation in Tumors Substantial and specific target-mediated proliferation of CD20 CAR T cells in localized lymphoma tumors at 6 days post treatment Blood Spleen Liver Bone marrow Tumor Cell Number T

cell Proliferation Day 2 Post-treatment CAR-T Day 6 Post-treatment CAR-T Blood Spleen Liver Tumor Bone marrow T cell Proliferation T cell Proliferation Day 6 Post-treatment CAR-T internal Adicet study

103 104 105 106 103 104 105 106 103 104 105 106

Intravenous Raji Tumor in SRG-15

Mice Absence of GvHD with CD20 CAR T Cells No GvHD observed in mice treated with T cells T cells not expected to induce GvHD in clinical study No gene editing required to overcome GvHD with

T cells CAR-T cell group succumbed to GvHD CART cells CAR T cells Tumor alone Days Post Treatment Percentage Surviving internal Adicet study; SRG-15 mice express human IL-15 transgene

ADI-001 (Off-the-shelf CD20 CAR

T cells) Opportunity Significant unmet medical need following CAR-T approvals Gr3+ CRS: 13-49%; Gr3+ neurotoxicity: 18-31% Limited number of specialized centers can treat patients; Suboptimal patient access Significant percentage of

patients in pivotal trials didn't receive cells (primarily due to mfg. challenges or wait time) 40% of patients treated with approved autologous CD19 CAR T therapy show durable responses ADI-001 Target product profile Effective (ORR, PFS/OS)

in CD20 expressing NHL Facilitating adaptive and innate anti-tumor immune responses with more limited ability for tumor escape Potential alternative to autologous therapies and/or line of therapy before/after CD19 cell therapy relapse Significantly

lower cytokine release syndrome; No GvHD Potential for outpatient administration Sources: Kymriah and Yescara package inserts; Neelapu et al. N Eng J Med 2017

Follow-up First in Human Study for

ADI-001 (CD20 CAR T cells) 20 Day -5 Day 0 Day 28 Month 12 Lymphodepletion Regimen: Flu/Cy Fludarabine: 30 mg/m2/d x 3 days, Cyclophosphamide 500 mg/m2/d x 3 days Phase 1 study design NHL patients relapsing from 2 or more prior lines of