A protein found on certain types of cells that binds to a substance called epidermal growth factor. The EGFR protein is involved in cell signaling pathways that control cell division and survival. Sometimes, mutations (changes) in the EGFR gene cause EGFR proteins to be made in higher than normal amounts on some types of cancer cells. This causes cancer cells to divide more rapidly. Drugs that block EGFR proteins are being used in the treatment of some types of cancer. EGFRs are a type of receptor tyrosine kinase. Also called epidermal growth factor receptor, ErbB1, and HER1.