Regarding sensitivity to CDK 4/6 inhibitors, a preclinical study showed that, following Palbociclib treatment, RCC cells underwent G0/G1 cell-cycle arrest and late apoptosis, and loss of CDKN2A, CDKN2B, and E2F1 was significantly associated with Palbociclib sensitivity [74]. The gene discussed is CDKN2A; the disease is renal cell carcinoma.