RB1 and small cell lung carcinoma: Among the main molecular subtypes, one exhibited SCLC-like features characterized by TP53/RB1 co-mutation or deletion, accompanied by amplification of MYCL, SOX2, and FGFR1 as well as PTEN mutation/deletion, and shared several clinicopathological characteristics with traditional SCLC, including higher proliferation activity and shorter relapse-free survival (RFS).