ERBB2 and breast cancer: The efficacy of cyclin-dependent kinase (CDK) 4/6 inhibitors in treating breast cancer is well established, making them the first-line therapy for hormone receptor-positive/human epidermal growth factor receptor 2 negative (HR+/HER2−) breast cancer (Pavlovic et al., 2023; Mayer et al., 2021; Lee et al., 2023).