In contrast, the prescribing indication for abemaciclib is quite different, it can be used in combination with fulvestrant for the treatment of women with HR-positive, HER2-negative advanced/metastatic BC previously progressed on ET, and as monotherapy for patients previously treated with ET and chemotherapy in metastatic setting (Table 1) [55,69,70,71,72,73]. The gene discussed is ERBB2; the disease is breast cancer.