CDK1 and neoplasm: Although RNAi knockdown of each of the CDKs (CDK1, CDK2, and CDK9) reduced TNBC tumor growth, and likely that dinaciclib exerted its anti-tumor activity in TNBC by inhibiting all the above CDKs, the finding that CDK9 knock down reduced the expression levels of MYC and Cyclin B1, as well as, tumor growth.