United States securities and exchange commission logo

                           October 22, 2021

       Eli Casdin
       Chief Executive Officer and Director
       CM Life Sciences III Inc.
       c/o Corvex Management LP
       667 Madison Avenue
       New York, New York 10065

                                                        Re: CM Life Sciences
III Inc.
                                                            Amendment No. 1 to
Registration Statement on Form S-4
                                                            Filed October 4,
                                                            File No. 333-259054

       Dear Mr. Casdin:

             We have reviewed your amended registration statement and have the
       comments. In some of our comments, we may ask you to provide us with
information so we
       may better understand your disclosure.

              Please respond to this letter by amending your registration
statement and providing the
       requested information. If you do not believe our comments apply to your
facts and
       circumstances or do not believe an amendment is appropriate, please tell
us why in your

              After reviewing any amendment to your registration statement and
the information you
       provide in response to these comments, we may have additional comments.
Unless we note
       otherwise, our references to prior comments are to comments in our
September, 2021 letter.

       Amendment No. 1 to Form S-4 filed October 4, 2021

       Background of the Business Combination, page 187

   1.                                                   We note your response
to our prior comment 7 and reissue in part. We note your statement
                                                        that the "preliminary
discussions [with Company A] were preliminary in nature and were
                                                        conducted without
exclusivity arrangements." However, investors need to know what
                                                        terms were important to
the Registrant during negotiations with Company A to understand
                                                        why EQRx was ultimately
superior. Please expand your disclosure to include the potential
                                                        terms discussed with
Company A. Additionally, please discuss the overlap of
                                                        the discussions with
Company A, which ended on May 27, 2021 and with EQRx, which
                                                        began on April 26,
2021, including when the CMLS III Board became aware of Mr.
 Eli Casdin
FirstName  LastNameEli
CM Life Sciences III Inc.Casdin
October 22,NameCM
            2021     Life Sciences III Inc.
Page 2 22, 2021 Page 2
FirstName LastName
         Casdin   s discussions and the considerations the Board evaluated
regarding Mr. Casdin   s
         role as an interested party.
Certain EQRx Projected Financial Information, page 202

2.       We note your response to our prior comment 12 and reissue. Please
expand your
         disclosure on page 203 to discuss the dates you expect the respective
products to receive
         regulatory approval in each market, the related cost of sales and net
income for 2026 and
         2028, the possible impact if your assumptions are incorrect, and
identify the probabilities
         assigned to management   s assumptions. Please also clarify whether
you have considered
         multiple scenarios and how they were weighted.
3.       We note the additional value that you expect from the unidentified
in-licensed assets you
         plan to acquire. Please disclose that there is no guarantee that you
will identify the
         requisite number of suitable assets and that even if you do, you may
not be able to acquire
         these assets or you may not be able to acquire them on terms that will
produce the
         projected returns. Please also disclose, if true, that the market
share projections are based
         on your untested pricing model.
EQRx's Business, page 253

4.       We note your response to our prior comment 13 and reissue. However,
neither of these
         statements provide a basis for how you arrived at the success rates of
5-7 out of 10 drug
         candidates and 3-5 out of 10 drug candidates. Please revise to provide
the basis by which
         you arrived at the numeric value of those rates, or remove the
statements. Please revised
         the founders letter to state there is no guarantee the suggested
success rate will be
The EQRx Business Opportunity, page 261

5.       We note your response to our prior comment 15 and reissue. The
revision does not
         address our comment regarding the size of the market for the products
         are currently developing. Please also balance the disclose added on
page 261 with the fact
         that there is no guarantee you will identify and successfully acquire
ten or more additional
         programs in the next twelve months.
Time for something new - time for "New Pharma", page 262

6.       We note your response to our prior comment 16 and your revisions.
However, there are
         still multiple statements in your disclosure of "equivalent or
superior." Given the early
         stage of development of your programs, these statements are
inappropriate. Please either
         provide the basses to support these statements, or remove.
Building a catalog of affordable medicines, page 270

7.       We note your response to our prior comment 18 and reissue. Your
revision does not
         address our comment to describe the basis for your projections, nor
does it address our
 Eli Casdin
CM Life Sciences III Inc.
October 22, 2021
Page 3
         comment to describe the underlying assumptions behind the projections.
Additional information on our pipeline programs, page 278

8.       We note your response to our prior comment 21 and your disclosure
regarding the severe
         adverse events observed in the aumolertinib and the sugemalimab
trials. Please expand
         your disclosure to identify the severe adverse events and the number
of patients that
         experienced severe adverse events.
9.       To the extent that you have not conducted head-to-head clinical
trials, please revise your
         disclosure to remove comparisons of your product candidates to other
treatments, products
         and product candidates. As but one example, we note your statements on
page 281 that
         "The tolerability profile was acceptable and comparable to other
immune checkpoint
         inhibitors." Additionally, we note your statement on page 278 that you
believe that
         aumolertinib has "demonstrated clinically meaningful activity and an
         tolerability profile." Statements regarding efficacy and safety are
determinations that only
         the FDA or a foreign government equivalent has the authority to make.
Please revise your
         disclosure throughout your document, including but not limited to the
statement noted, to
         eliminate your conclusions or any suggestions that your product
candidates have been or
         will ultimately be determined safe and/or effective or have
demonstrated safety and/or
         efficacy for purposes of granting approval by the FDA or comparable
agency. You may
         present the objective data from the clinical trials without drawing a
conclusion from the
Certain Material U.S. Federal Income Tax Considerations, page 398

10.      We note your response to our prior comment 24 and the revised
disclosure on page 399.
         Please explain why counsel cannot give a "will" opinion with respect
to whether the
         Business Combination qualifies for U.S. federal income tax purposes as
            reorganization    within the meaning of the IRC. If counsel intends
to provide a "should"
         opinion, please (1) revise the disclosure to describe the degree of
uncertainty and explain
         the facts or circumstances giving rise thereto and (2) add risk factor
and/or other
         appropriate disclosure setting forth the risks of uncertain tax
treatment to investors. For
         guidance, see Section III.C.4 of Staff Legal Bulletin No. 19.


11.    We note your response to our prior comment 25 and do not agree that
these agreements
       are not required to be filed as an exhibit to your registration
statement. Throughout your
       prospectus, you reference the importance of building a portfolio of
FirstName LastNameEli Casdin
       programs, including these specific preclinical programs. Given the
importance of these
Comapany    NameCM
       programs   to theLife Sciencesfuture
                         company's     III Inc.
                                             success, it appears that you are
substantially dependent
Octoberupon  them.Page 3
         22, 2021
FirstName LastName
 Eli Casdin
FirstName  LastNameEli
CM Life Sciences III Inc.Casdin
October 22,NameCM
            2021     Life Sciences III Inc.
Page 4 22, 2021 Page 4
FirstName LastName
       You may contact Ibolya Ignat at 202-551-3636 or Kevin Vaughn at
202-551-3494 if you
have questions regarding comments on the financial statements and related
matters. Please
contact Jordan Nimitz at 202-551-6001 or Christopher Edwards at 202-551-6761
with any other


                                                        Division of Corporation
                                                        Office of Life Sciences
cc:      Joel Rubinstein, Esq.