CD8A and colorectal carcinoma: Ultimately, IFN-γ production in CD4+ and CD8+ TIL was enhanced upon PMA-ionomycin restimulation after in vitro culture with the combination regimen as well as TNF-α production in CD4+ TIL, indicating that GITR co-stimulation improves anti-PD1-mediated immune stimulation in pMMR CRC-derived TIL (Figure 11C and D).