The inhibition of other CDKs such as CDK8/19 and CDK9 has demonstrated preclinical efficacy in BC, including models of TNBC and of endocrine‐ and CDK4/6i‐resistant HR+/HER2−–BC, but this strategy has not yet rendered clinical data.90, 91, 92, 93. This evidence concerns the gene ERBB2 and breast cancer.