The ErbB family of receptors, also known as the Epidermal Growth Factor Receptor (EGFR) family, consists of four closely related receptor tyrosine kinases: EGFR (ErbB1), HER2 (ErbB2), HER3 (ErbB3), and HER4 (ErbB4). These receptors play a crucial role in cell growth, differentiation, and survival. They are activated by binding to specific ligands, leading to receptor dimerization and autophosphorylation, which triggers a cascade of downstream signaling pathways.