Rock Springs Capital Management LP - Oct 21, 2021 Form 3 Insider Report for Xilio Therapeutics, Inc. (XLO)

Role: 10%+ Owner
Signature: By: /s/ Mark Bussard, Authorized Signatory, Rock Springs Capital Management LP
Stock symbol: XLO
Transactions as of: Oct 21, 2021
Transactions value $: $0
Form type: 3
Date filed: 10/21/2021, 08:51 PM
Previous filing: Oct 14, 2021
Next filing: Oct 26, 2021

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
holding	XLO	Series C Preferred Stock							Oct 21, 2021	Common Stock	756K		See footnote	F1, F2
holding	XLO	Series C Preferred Stock							Oct 21, 2021	Common Stock	151K		See footnote	F1, F3

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	The Series C Preferred Stock automatically converts into the number of shares of Common Stock as shown in Column 3 without payment of further consideration at the holder's election or upon closing of the initial public offering of the Issuer's common stock. The shares have no expiration date.
F2	The securities reported herein are held of record by Rock Springs Capital Master Fund LP ("Master Fund"). Rock Springs Capital LLC ("RSC") is the general partner of Rock Springs Capital Management LP ("RSCM") which is the investment manager to Master Fund. RSC and RSCM may therefore be deemed to have or share beneficial ownership of the Series C Preferred Stock held directly by Master Fund.
F3	The securities reported herein are held of record by Four Pines Master Fund LP ("Four Pines"). RSC is the general partner of RSCM which is the investment manager to Four Pines. RSC and RSCM may therefore be deemed to have or share beneficial ownership of the Series C Preferred Stock held directly by Four Pines.