Dinaciclib, a multi-target Cdk1, Cdk2, Cdk5 and Cdk9 second-generation inhibitor, leads to the arrest of cell-cycle progression and induces apoptosis in various tumor cells.4,7In vivo studies indicate that dinaciclib indeed has anti-tumor effects and reduces tumor growth.4,8 Saqub et al. already showed that dinaciclib is able to prevent proliferation of tumor cells in vitro and in vivo. Here, CDK9 is linked to neoplasm.