The EGF receptor - an essential regulator of multiple epidermal functions.

Epidermal keratinocytes express both the epidermal growth factor receptor (EGFR) and several of its ligands, establishing the constitutive elements of an autocrine loop in this cell type. Activation of the EGFR provides signals essential to several aspects of normal keratinocyte biology including cell cycle progression, differentiation, cell movement and cellular survival. It may be argued that enhanced keratinocyte survival via EGFR activation is the most important function as it limits the manifestation of other phenotypes. The frequent deregulation of EGFR expression and activation in benign and malignant hyperproliferative skin diseases motivates the investigation of EGFR-dependent intracellular pathways which contribute to the varied EGFR-dependent phenotypes.