Epidermal Growth Factor Receptor (EGFR) signaling pathway is used multiple times during development (FBrf0190321). It is activated by the binding of a secreted ligand - the transforming growth factor-α-like ligands:spi, Krn, grk or the neuregulin-like ligand vn, to the receptor tyrosine kinase Egfr. The pathway can be regulated by the maturation and secretion of TGF-α-like ligands. The EGFR signaling pathway acts via the canonical Ras/Raf/MAP kinase (ERK) cascade. (Adapted from FBrf0190321 and FBrf0221727).