RB1 and small cell lung carcinoma: Currently, the understanding of lung neuroendocrine cancer centers on SCLC and carcinoids representing entirely unrelated tumor entities, occurring in distinct patient populations (younger, never-smokers for carcinoids vs. older smokers for SCLC), and characterized by highly distinct genomic profiles, most notably separated by RB1 and TP53 genomic status and TMB (12).