SCLC is strongly associated with smoking and therefore has a relatively high tumor mutation burden (TMB), suggesting that it might be responsive to immune checkpoint inhibitors (ICIs).9, 10, 11, 12 Nevertheless, only approximately 20% of SCLC tumors have a tumor proportion score for PD-L1 of more than or equal to 1%.13, 14, 15, 16 A better understanding of the transcriptomic and genomic features of SCLC is therefore needed to inform the development of optimal therapeutic strategies. This evidence concerns the gene CD274 and neoplasm.