Two studies were conducted with individuals diagnosed with HER2-positive metastatic BC (Pivot et al., 2017; Ciruelos et al., 2020) and the remaining three were with individuals diagnosed with HER2-positive eBC (Pivot et al., 2014; O’Shaughnessy et al., 2021; Reinisch et al., 2022). The gene discussed is ERBB2; the disease is breast cancer.