In contrast, the immune evasion process led by PD-1/ PD-L1 axis is primarily attributed to the overexpressed PD-L1 on cancer cells which binds to PD-1 expressed on antigen-stimulated T cells and inhibited the activity of PI3K/AKT and Ras/MEK/ERK signaling pathways. This evidence concerns the gene PDCD1 and cancer.