Among them, palbociclib, ribociclib, abemaciclib, and dalpiciclib are employed in combination with endocrine therapy for HR-positive (HR+)/HER2-negative (HER2-) locally advanced or metastatic breast cancer [6], while trilaciclib is utilized as preventive therapy prior to chemotherapy in patients with extensive-stage small-cell lung cancer (ES-SCLC) to reduce the incidence of bone marrow suppression [7]. The gene discussed is ERBB2; the disease is small cell lung carcinoma.