EGFR and cancer: In cancer, for example, ligand binding activates EGFR signaling, resulting in homodimerization or heterodimerization with another member of EGFR’s family and phosphorylation of EGFR, which activates downstream signaling, such as PI3K/AKT signaling cascades, RAS/RAF/MEK/MAPK signaling pathway, and JAK/STAT signaling pathway (Wallasch et al., 1995; Garrett et al., 2003).