PDCD1 and neoplasm: Although CD226 transcripts in CD112R−/−CD8+ TILs did not appear to be up-regulated in an MC38 tumor model (colon cancer) [31], several inhibitory receptors, including TIGIT, Tim-3, PD-1, and LAG-3, were highly expressed on CD8+ T cells that infiltrated the CD112R−/− mouse tumors compared to the wild-type CD8+ T cells [31].