RB1 and neoplasm: The histopathological features of Rb/p53/Rbl2-mutant tumors also resembled those of human SCLC, while more tractable features, including a relatively short latency, make this Rb/p53/p130-mutant model useful for studying the mechanisms of SCLC initiation, progression, metastasis, and tumor immunity and a novel preclinical mouse model for testing new therapeutics against SCLC91–95.