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 June 2, 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 most recent Annual Report on Form 10-K filed with the U.S. Securities and Exchange Commission (the "SEC"), 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 will file relevant materials with the U.S. Securities and Exchange Commission (the "SEC"), including a

registration statement on Form S-4 (the "Form S-4") that will contain a proxy statement (the "Proxy Statement") and prospectus. This communication is not a substitute for the Form S-4, the Proxy 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 PROXY 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 Proxy 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 its Annual Report on Form 10-K for the year ended December 31, 2019, which was filed with the SEC on March 12, 2020, its proxy statement for its 2020 annual meeting of

stockholders, which was filed with the SEC on March 27, 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 Proxy 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.

Deal Rationale: About Adicet Bio

Developing off-the-shelf, engineered Gamma-Delta ( ) CAR-T cell therapy pipeline for oncology and other indications. Key anticipated advantages of Adicet's CAR-T cell therapy: 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 Off-the-shelf with potential to re-dose patients and with no expected GvHD cGMP-compliant

manufacturing from healthy donors Proprietary T Cell Receptor-Like (TCR-L) monoclonal antibodies platform targeting intracellular targets presented on MHC complexes Established Partnership with Regeneron Leadership Team With Significant Operational

and Development Expertise Post-merger Entity Expected to be Well Capitalized Into 2022 CAR: Chimeric Antigen Receptors; NK: Natural Killer; GvHD: Graft Versus Host Disease; NKG2D: NK Group 2D; NCR=Natural Cytotoxicity Receptors; DNAM-1: DNAX

accessory molecule-1 CAR DNAM-1 NCRs NCRs NKG2D

resTORbio/Adicet Bio Merger Close

expected 2H 2020 New company expected to be listed on NASDAQ (ticker TBD) Board of Directors expected to include five designated by Adicet + one from resTORbio + CEO On a pro forma basis, current Adicet equityholders are expected to own

approximately 75% of the combined company and current resTORbio equityholders are expected to own approximately 25% of the combined company

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

Building a Broad Pipeline of First in

Class CAR T Cell Therapy NH: Non-Hodgkin's ; HCC: Hepatocellular Carcinoma 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

Adicet Strategic Priorities File IND

for ADI-001 CD20 gamma-delta CAR-T Initiate Phase 1 clinical study in non-Hodgkin's lymphoma File IND for ADI-002 GPC3 gamma-delta CAR-T Initiate Phase 1 in hepatocellular carcinoma Expand pipeline in oncology and other diseases Achieve

milestones from collaboration with REGN

Key Anticipated Advantages of

Adicet's Allogeneic T Cell Platform 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 T cells express multiple

tumor-recognizing receptors CAR DNAM-1 NCRs NCRs NKG2D

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

Anticipated Differentiation From

Other Allogeneic CAR-T Ideal Allogeneic CAR-T Therapy Attributes Allogeneic CAR T Cells Allogeneic CART T Cells Potency Recognize and bind tumor Predominantly CAR-mediated CAR and Multiple innate receptors Effectively kill

tumor Predominantly CAR-CD8 T subset All V 1 T cells* Active tumor homing Limited compared to normal tissues Tissue homing Safety No / low GvHD Requires deletion of TCR Yes No severe cytokine release syndrome Unlikely

Likely, due to limited IL-2 secretion Practicality Robust and cost effective manufacture Multiple gene edits required Minimal genetic manipulations required Scalable manufacture Limited without exhaustion Yes *Adicet's T cell

products are predominantly V 1 cells

Large-Scale Manufacture of

T Cells Simplify for Robustness, Partner for Capability and Capacity Leukopheresis from a qualified donor Activate desired subsets of T cells Engineer T cells with CARs Expand ICP Cell Bank of final "Off

the Shelf" ICP Treatment of multiple patients Production Process for Immune Cell Product (ICP)

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 Subcutaneous Mino 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 Subcutaneous Raji Tumor Growth Intravenous Granta Tumor Growth Intravenous Raji Tumor Growth * * * * internal Adicet study

Effectively Control Repeat Lymphoma Challenges 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 continue to control tumor growth to 100 days * internal Adicet study

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

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

Clinical Development Plan of ADI-001

Phase 1 study design NHL patients relapsing from 2 or more prior lines of treatment ~3 cohorts for dose escalation/safety Up to 50 patients at the selected dose Single treatment with ADI-001 Option for retreatment in select patients Pivotal study

likely in DLBCL and/or MCL Target product profile of ADI-001 (CD20 CAR T cells derived from healthy donor) Effective (ORR, PFS/OS) in CD20 expressing NHL Significantly lower cytokine release syndrome No GvHD

ADI-001 Status Pre-IND meeting

completed IND application enabling activities in process ADI-001 IND application preparation in process Proposed ADI-001 clinical trial design well received by key centers and KOLs Preparations for ADI-001 Phase 1 Clinical study underway

Additional Pipeline in Solid Tumors:

Anticipated Advantages of

Adicet's CAR-T Cell Therapy in Solid Tumors Solid Tumor Therapy Goal Adicet CAR-T Cell Anticipated Advantage Avoiding autologous cell exhaustion / dysfunction Healthy CMV-negative donor derived product preserves

V 1 proliferative capacity Potential for >30 population doublings ex vivo / in vivo Specific tumor-induced activation & proliferation Activation-induced PD-1 expression is reversible without exhaustion CAR-designs minimize tonic

signaling Cells Infiltration into Tumor Chemokine receptor and adhesion molecule mediated infiltration Immunosuppressive Tumor Microenvironment Further engineering can improve responses to tumor microenvironment factors Loss of HLA or Target