Consistent with our hypothesis, in our cohort of 507 patients with a variety of cancers harboring G1/S phase cell-cycle gene alterations (CDK4/6 amplifications, CCND1/2/3 amplifications, or CDKN2A/B alterations), 99% of patients (n = 501) had at least one genomic co-alteration (median, 4; range, 0–24). The gene discussed is CDKN2A; the disease is cancer.