In a recent whole-exome sequencing (WES) study, alterations in numerous genes including AKT1 and ERBB2, RAS pathway activating alterations, AURKA and CCNE2 amplification, and FGFR2 alterations were identified in tumor biopsies from patients with intrinsic or acquired CDK4/6i resistance [6]. The gene discussed is CCNE2; the disease is neoplasm.