7. PD-L1 expression in tumor tissue from any site is required for patients with NSCLC. Tumor tissue can be archival, however if no archival tissue is available then a biopsy mube obtained for PD-L1 testing. PD-L1 expression will be analyzed by a Merck assay. PD-L1 expression is not required for patients with melanoma, but melanoma patients are required to submit an extra-cerebral specimen for analysis, unless it is not feasible to obtain one.