RB1 and neoplasm: Retinoblastoma (RB) gene, a well-studied tumor suppressor, plays important roles in cell-cycle regulation and other cellular processes.1, 2, 3 Loss or dysfunction of RB is a common feature in various tumors, and contributes to tumor cell stemness and drug resistance.4, 5 Therefore, it is urgent to explore a way to suppress RB-deficient tumor cells.