CDK1 and plasma cell myeloma: Dinaciclib, identified as a candidate drug in the 4,560-drug screen, was also investigated because the Cdk (Cdk1, 2, 5, 9, and 12) inhibitor dinaciclib was reported as an encouraging single agent in multiple myeloma (24), and the Cdk2/9 inhibitor showed efficacy in CCC organoids (Fig. 2D).