RB1 and small cell lung carcinoma: Rekhtman et al. classified LCNEC into SCLC‐like, NSCLC‐like, and carcinoid‐like subset based on gene mutational profiles using custom targeted sequencing panels.13 In their study, 40% of LCNEC showed SCLC‐like gene mutational profile, characterized by coalteration of TP53 and RB1 (retinoblastoma‐related gene 1), 56% of LCNEC exhibited NSCLC‐like gene mutational profile, characterized by the lack of TP53 and RB1 coalteration and the presence of STK11/KRAS mutations.