HER2 is part of the epidermal growth factor receptor (EGFR/Erb) family of tyrosine kinase receptors, which consists of four members-EGFR/HER1/ErbB1, HER2/ErbB2, HER3/ErbB3, and HER4/ErbB4-and is closely related to cell proliferation, differentiation, migration, and cancer development (Roskoski, 2019; Sabbah et al., 2020). The gene discussed is EGFR; the disease is cancer.