Three immunohistochemical platforms were used to assess laboratory-developed tests (QR1, 22C3) and standardized PD-L1 assays [22C3, 28-8, SP142, SP263 (Ventana)] using a training set of tonsil tissue and seven metastatic melanomas in formalin-fixed paraffin-embedded blocks, which showed a range of PD-L1 staining intensities. The gene discussed is CD274; the disease is metastatic melanoma.