In addition, activation of immune checkpoints, such as the PD-L1/PD1 axis (PD1 is a T-cell co-suppressor molecule and checkpoint protein), also causes loss of CD8+TILs effector function; this can lead to CD8+T cell depletion and tumor evasion of the immune system, leading to tumor progression and metastasis [5, 6]. Here, CD8A is linked to neoplasm.