Human epidermal growth factor receptor 2 (ErbB2, HER2, or neu) is overexpressed on the cellular surface of tumors (Roy et al., 2019; Işık and Barut, 2020; Egebjerg et al., 2021; Omranipour et al., 2021), especially in breast (Oh and Bang, 2020) and gasteric (Boku, 2014) cancers. The gene discussed is ERBB2; the disease is cancer.