CD8A and prostate cancer: Vesicular PD-L1 promotes CD8+ T-cell apoptosis via PD-1/PD-L1 and PD-L1/CD80 signaling pathways [176], blocks T-cell activation in the draining lymph node in TRAMP- C2 prostate cancer mouse model [177,178], and reduces the proliferation of CD8+ T cells by decreasing IL- 2 and IFN-γ in the TME [136].