EGFR encodes a receptor tyrosine kinase that is involved in the regulation of cell growth, survival, and differentiation. It is activated by binding to its ligands, such as epidermal growth factor (EGF), and mediates downstream signaling pathways that control cellular processes like proliferation, migration, and differentiation. EGFR is critical in normal development, wound healing, and tissue repair. However, mutations or overexpression of EGFR are associated with various cancers, including non-small cell lung cancer (NSCLC), making EGFR a target for cancer therapies, including monoclonal antibodies and tyrosine kinase inhibitors.
The protein encoded by this gene is part of the T-cell receptor/CD3 complex (TCR/CD3 complex) and is involved in T-cell development and signal transduction. The encoded membrane protein represents the delta subunit of the CD3 complex, and along with four other CD3 subunits, binds either TCR alpha/beta or TCR gamma/delta to form the TCR/CD3 complex on the surface of T-cells. Defects in this gene are a cause of severe combined immunodeficiency autosomal recessive T-cell-negative/B-cell-positive/NK-cell-positive (SCIDBNK). Two transcript variants encoding different isoforms have been found for this gene. Other variants may also exist, but the full-length natures of their transcripts has yet to be defined.