RB1 and small cell lung carcinoma: In CheckMate 032, patients (n = 460) with RB1 WT after Nivolumab treatment had significantly improved prognosis, compared with those with RB1 mutation (HR, 1.41; P = 0.041) and longer OS in patients with low RB1 loss of function feature scores (43), suggesting RB1 mutation status as a potential biomarker for SCLC immunotherapy.