POWER OF ATTORNEY
Know all by these presents, that the undersigned hereby constitutes and appoints
each of
John West, Aaron Tachibana, Stephen Moore, Michael Tenta, Allison Peth, Jacob
Hanna
and Kristin Peardon, with full power of substitution, signing individually,
the undersigneds true and lawful attorneys-in fact and agents to:

(1) execute for and on behalf of the undersigned, in the undersigneds
capacity as an officer, director or beneficial owner of more than 10% of a
registered class of securities of Personalis, Inc., Forms 3, 4, and 5
(including any amendments thereto), relating to the securities of Personalis,
Inc.,
in accordance with Section 16(a) of the Securities Exchange Act of 1934, as
amended (the Exchange Act)
and the rules thereunder and a Form ID, Uniform Application for Access Codes to
File on EDGAR;

(2) do and perform any and all acts for and on behalf of the undersigned that
may be
necessary or desirable to execute such Forms 3, 4, or 5, or Form ID (including
any amendments thereto)
and timely file such forms with the United States Securities and Exchange
Commission
and any stock exchange or similar authority; and

(3) take any other action of any nature whatsoever in connection with the
foregoing which, in the opinion of such attorney-in-fact, may be of benefit,
in the best interest of, or legally required by, the undersigned, it being
understood that the documents executed by such attorney-in-fact on behalf
of the undersigned pursuant to this Power of Attorney shall be in such form
and shall contain such terms and conditions as such attorney-in-fact
may approve in such attorney-in-facts discretion.

The undersigned hereby grants to each such attorney-in-fact full
power and authority to do and perform any and every act and thing
whatsoever requisite, necessary or proper to be done in the exercise
of any of the rights and powers herein granted, as fully to all intents
and purposes as the undersigned might or could do if personally present,
with full power of substitution or revocation, hereby ratifying and confirming
all that such attorney-in-fact, or such attorney-in-facts substitute or
substitutes,
shall lawfully do or cause to be done by virtue of this power of attorney and
the rights
and powers herein granted. The undersigned acknowledges that the foregoing
attorneys-in-fact, in serving in such capacity at the request of the
undersigned, are not assuming, nor is Personalis, Inc. assuming,
any of the undersigneds responsibilities to comply with Section 16 of the
Exchange Act.


This Power of Attorney shall remain in full force and effect until the earliest
to occur
of (a) the undersigned is no longer required to file Forms 3, 4 and 5 with
respect to the undersigneds
holdings of and transactions in securities issued by Personalis, Inc., (b)
revocation by the undersigned
in a signed writing delivered to the foregoing attorneys-in-fact or
(c) as to any attorney-in-fact individually, until such attorney-in-fact is no
longer
employed by Personalis, Inc. or Cooley LLP.

The undersigned has caused this Power of Attorney to be executed as of February
12, 2021.


    /s/ Woodrow Augustus Myers Jr.