CDK4 and neoplasm: Interestingly, dinaciclib, an inhibitor against CDK1, 2, 5, and 9 (IC50 1-4nM), but with less activity against CDK4, 6, and 7 (IC50 60-100nM), showed encouraging anti-tumor effect in preclinical studies of TNBC with potential selectivity for MYC driven tumors [13, 14].