CD8A and neoplasm: A dose of αPD-L1 (3 μg per injection) with no therapeutic effect on MC38 tumors nonetheless significantly inhibited MC38 Rab27a−/− tumor growth, accompanied by a significant increase in IFN-γ+CD8+ and Ki-67+CD8+ T cells in TTs (Fig. 3h and Supplementary Fig. 3k).