EGFR and HER2 can form homodimers or heterodimers after activation to activate intracellular signaling pathways, such as RAS/RAF/MEK/ERK, PI3K/AKT/mTOR, Src kinase, and STAT transcription factors associated with tumorigenesis, cancer progression, and drug resistance27,28. The gene discussed is ERBB2; the disease is cancer.