The previously mentioned pRb variants that lack pRb/E2F transcriptional repressor complexes, along with RB1-null cells transfected with KDM5A siRNA, ultimately stop proliferating.86 Thus, although KDM5A inhibition would not restore pRb’s repressive effect on E2F, it could still serve to cease cancer cell proliferation in RB mutants via induction of a differentiation-like state. This evidence concerns the gene RB1 and cancer.