Current research indicates that nearly 50% of patients with HER2-negative breast cancer are classified as HER2-low, thereby enabling them to benefit from novel anti-HER2 treatments (Marchio et al., 2021; Modi et al., 2022; Xin et al., 2022; Zhang et al., 2022; Yang et al., 2023). The gene discussed is ERBB2; the disease is breast cancer.