Currently, there are several FDA-approved immunohistochemical (IHC) assays for PD-L1 expression in urothelial carcinoma: Ventana SP142 (Atezolizumab), Ventana PD-L1 SP263 (Durvalumab), 22C3 pharmDx (Pembrolizumab) and 28-8 pharmDx (Nivolumab). The gene discussed is CD274; the disease is urothelial carcinoma.