The oral cyclin‐dependent kinases 4 and 6 (CDK4/6) inhibitors, palbociclib, ribociclib, and abemaciclib, have significantly improved the progression‐free survival of hormone receptor (HR)‐positive, HER2‐negative (HR+/HER2‐) metastatic or advanced breast cancer patients when combined with endocrine therapy.[11, 12, 13, 14, 15, 16] The therapeutic landscape further expanded with the monarchE trial,[17, 18] in which abemaciclib demonstrated efficacy not only in metastatic settings but also in HR‐positive, high‐risk early‐stage breast cancer. This evidence concerns the gene CDK4 and breast cancer.