EGFRn

EGFRn is a designation used in some studies to describe a variant or isoform related to the epidermal growth factor receptor (EGFR), a receptor tyrosine kinase in the ERBB family. The term does not have a universal definition and different authors may use it to refer to distinct entities, such as a splice variant of EGFR or a paralogous gene with homology to EGFR. Because of this variability, the precise sequence, expression pattern, and function attributed to EGFRn can differ across reports.

In descriptions where it is used, EGFRn is expected to share the characteristic topology of EGFR family members: an extracellular ligand-binding domain, a single-pass transmembrane segment, and an intracellular tyrosine kinase domain. Differences may include alternative splicing at the C-terminal tail, truncations, or alterations in the ligand-binding region, which can modulate ligand affinity and downstream signaling.

EGFRn may originate from alternative splicing of the EGFR gene or from a related gene with partial homology. Reported expression is often context-dependent, with detections in certain cancer cell lines or neural tissues in some studies.

As with EGFR, signaling is proposed to involve activation of canonical pathways such as MAPK/ERK, PI3K/AKT, and STATs, leading to effects on proliferation, survival, and differentiation. The functional impact of EGFRn depends on the integrity of the kinase domain and regulatory regions.

In oncology research, EGFRn variants are examined for potential roles in tumor biology and drug resistance or as diagnostic markers. Tools used include transcript-specific PCR, isoform-specific antibodies, and CRISPR-based disruption to study function.

See also: Epidermal growth factor receptor; ERBB family; EGFRvIII. References: to be added.