CEA526–533 and HIV-GAG tetramer staining were performed as previously described (1 (link)). To analyze TIMs, 21-day-old MC38-CEA tumors were harvested and enzymatically digested to obtain a single-cell suspension (1 (link)). Anti-CD11b Alexa Fluor 700 clone M1/70 and anti-Gr1 APC-Cy7 clone RB6-8C5 were purchased from BD Biosciences (Franklin Lakes, NJ). Anti-CXCL9 Alexa Fluor 647 clone MIG-2F5.5, anti-CD105 PerCp-Cy5.5 clone MJ7/18, and anti-CD31 Pacific Blue clone 390 were purchased from BioLegend (San Diego, CA). Anti-CD45 eFluor 605NC clone 30-F11 and anti-FAS-L PerCP-eFluor 710 clone MFL3 were purchased from eBioscience (San Diego, CA). At least 3 × 105 live cells were acquired with an LSR-II flow cytometer (BD Biosciences) and data were analyzed with FlowJo software for PC (TreeStar Inc., Ashland, OR).