Among women, the most common type of breast cancer is the hormone receptor-positive/human epidermal growth factor receptor 2 negative (HR+/HER2−-) breast cancer, where CCND1 as an encoding of cyclin D1, the catalytic subunit of CDK4 and CDK6, is profoundly expressed [5,6,7]. The gene discussed is CCND1; the disease is breast carcinoma.