A comparison of TILs in each tumor type revealed that while the ratio of CD8+ T cells to Treg was markedly increased after treatment of 4T1 and CT26 tumors, this was not the case for MC38 tumors (8.51 and 4.84, respectively compared with 1.30; online supplemental figure 3), indicating that immunosuppression in MC38 tumors cannot be overcome by targeting PI3Kδ. This evidence concerns the gene CD8A and neoplasm.