RB1 and small cell lung carcinoma: Similarly, George and colleagues performed a comprehensive molecular analysis of 75 pulmonary LCNECs (19 with combined histology), identifying two distinct genomic subgroups with specific transcriptional patterns: type I LCNEC (37%), characterized by TP53 and STK11/KEAP1 alterations, similar to lung adenocarcinoma and squamous cell carcinoma [23,24,30], and type II LCNEC (42%), with concurrent inactivation of TP53 and RB1, typical of SCLC [15].