On the grounds of the association of PD-L1 tumor expression with response to anti-PD-1 agents in solid malignancies (melanoma, non-small cell lung cancer) (Di Lorenzo et al., 2016) and of PD-L-1 expression in penile cancer patients (Udager et al., 2016), pembrolizumab will be tested in a single-arm phase II study (ClinicalTrials.gov Identifier: NCT02837042) in PSCC patients. This evidence concerns the gene CD274 and squamous cell carcinoma of penis.