“Insulin Receptor” was the subject of an earlier blog post. Here I present a continuation of that class of proteins. “EGFR: Epidermal Growth Factor Receptor”, Enzyme Commission 18.104.22.168, Receptor Tyrosine Kinase is at location “V” (end of the chart), and coordinate “6” (shown in diagram above at the edge) on the Roche Biochemical webpage. The epidermis is the outer epithelial layer of a human, and is a complex stratified epithelium. EGFR is the standard gene symbol for the genetic locus which is located on chromosome #7 in humans. The EGFR is composed of allele variation at the locus. One polymorphism of EGFR is responsible for the “eyelid fold” of Japanese and other mongoloid people.