PDCD1 and urothelial carcinoma: Since 2016, up to five different ICIs targeting programmed cell death protein 1 (PD-1), i.e., pembrolizumab and nivolumab, or programmed cell death ligand 1 (PD-L1), i.e., atezolizumab, avelumab and durvalumab, are approved by FDA for the treatment of late-stage urothelial carcinoma.