Catherine et al. identified a novel CDK2 inhibitor, INX-315, and utilized patient-derived xenograft (PDX) and transgenic mouse models to demonstrate its efficacy in both Cyclin E1 (CCNE1)-amplified cancer and CDK4/6i-resistant breast cancer, thereby presenting a potential strategy for cancer cells to evade growth inhibition [109]. The gene discussed is CCNE1; the disease is breast carcinoma.