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                          November 15, 2022

       Rene Russo
       Chief Executive Officer
       Xilio Therapeutics, Inc.
       828 Winter Street, Suite 300
       Waltham, MA 02451

                                                        Re: Xilio Therapeutics,
Inc.
                                                            Registration
Statement on Form S-3
                                                            Filed November 9,
2022
                                                            File No. 333-268264

       Dear Rene Russo:

              This is to advise you that we have not reviewed and will not
review your registration
       statement.

               Please refer to Rules 460 and 461 regarding requests for
acceleration. We remind you
       that the company and its management are responsible for the accuracy and
adequacy of their
       disclosures, notwithstanding any review, comments, action or absence of
action by the staff.

                                                        Please contact
Christine Westbrook at 202-551-5019 with any questions.




                          Sincerely,


                          Division of Corporation Finance

                          Office of Life Sciences
       cc:                                              Molly W. Fox, Esq.