The epidermal growth factor receptor (EGFR) is a protein found on the surface of cells. It plays a crucial role in cell growth, division, and survival by binding to specific molecules called epidermal growth factors. When these factors attach to EGFR, they trigger a series of signals inside the cell that promote various cellular activities. EGFR is important in many biological processes and is often studied in relation to certain diseases, particularly cancer. Abnormalities in EGFR can lead to uncontrolled cell growth, making it a target for specific therapies, such as monoclonal antibodies and tyrosine kinase inhibitors, used in cancer treatment.