MYC and neoplasm: It did not induce the degradation of other CDK proteins, including CDK1, CDK2, CDK4, CDK5, CDK6, and CDK7, at concentrations ranging from 100 to 500 nM in MDA-MB-231 cells.57 Compound 45 could markedly reduce CDK9 and MYC, inhibiting the growth of TNBC cells (MDA-MB-468, MDA-MB-231, and BT-549) in vitro and tumor growth of MDA-MB-231 xenografts in vivo.57