RB1 and neoplasm: We intraperitoneally injected immune compromised mice with either theTP53 mutant, RB misregulated, mitotic progression regulatory deficientARK1 model or the TP53 mutant, RB intact regulation, mitotic progressionregulatory proficient HEC1B model, followed carefully for tumor formation viabioluminescent imaging (BLI), and then began treatment with vehicle or either AURKBi orCDK4/6i respectively (Fig. 6A).