In human penile SCCs (peSCCs), the role of PD-1/PD-L1 has been explored by some studies that have emphasized that the expression of PD-L1 was associated with unfavorable disease-specific survival and that tumors with a diffuse PD-L1 tumor cell expression had a worse prognosis when compared to those with a marginal or negative PD-L1 expression. This evidence concerns the gene PDCD1 and neoplasm.