# What is an EGFR mutation in lung cancer, and why does it matter for treatment?

Source: https://oncologyistanbul.com/answers/what-is-an-egfr-mutation-in-lung-cancer
Last updated: 2026-07-13

According to the U.S. National Cancer Institute (NCI), EGFR (epidermal growth factor receptor) is a protein found on certain cells that binds epidermal growth factor and is involved in cell signaling pathways that control cell division and survival. NCI explains that mutations (changes) in the EGFR gene can cause EGFR proteins to be made in higher-than-normal amounts on some cancer cells, causing those cells to divide more rapidly. This matters for treatment because EGFR is a type of receptor tyrosine kinase, and drugs that block EGFR proteins are being used to treat some cancers. Checking a tumor for such targets — biomarker testing — helps determine whether a targeted therapy may be an option. This is general information, not personal medical advice.

## Verify at
- [NCI Dictionary of Cancer Terms — EGFR](https://www.cancer.gov/publications/dictionaries/cancer-terms/def/egfr) — National Cancer Institute (NCI) (checked 2026-07-13)
- [Targeted Therapy to Treat Cancer](https://www.cancer.gov/about-cancer/treatment/types/targeted-therapies) — National Cancer Institute (NCI) (checked 2026-07-12)

Related: [EGFR biomarker testing](https://oncologyistanbul.com/biomarkers/egfr)