To address the role of Cdk2 repression as a possible therapeutic target, we treated explanted Irbp-Cyclin D1, p18Ink4c -/- and Irbp-Cyclin D1, p53 -/- pineal tumor cells with the Cdk2-inhibitor CVT313, at a concentration of 5 μM, known to specifically inhibit Cdk2 [11,31]. This evidence concerns the gene CCND1 and pineal body neoplasm.