The analysis of the expression of Rb1 and p16INK4A in a panel of 263 epithelial ovarian cancer samples, by immunohistochemistry (IHC), demonstrated that low/null expression of p16INK4A and Rb1 were associated with shorter patients’ progression free survival [85] and suggested that these tumors could be the ones most benefitting from the treatment with CDK4/6i, alone or in combination with chemotherapy. This evidence concerns the gene RB1 and ovarian carcinoma.