CD274 and melanoma: In addition to the mutational status, reporting programmed death-ligand 1 (PD-L1) expression by immunohistochemistry is recommended for all unresectable stage III and IV melanoma, since the European Medicines Agency (EMA) has approved the administration of nivolumab–relatlimab only in patients with tumour cell PD-L1 expression <1%.2 Tumour mutational burden computed on full exome sequencing or on a large full-length panel and expressed as the number of mutations per megabase can be assessed and recorded, but its clinical use is currently not warranted.1