It was found that RB1 deletion and TP53 mutation were prevalent in patients who developed SCLC transformation, and the risk of SCLC transformation in patients with EGFR-mutated lung adenocarcinoma combined with RB1 deletion and TP53 mutation was 42.8 times higher than that in patients without RB1 deletion and TP53 mutation (13). The gene discussed is EGFR; the disease is lung adenocarcinoma.