Transgenic mice provide new insights into the role of TGF-alpha during epidermal development and differentiation.

The study used transgenic mice to investigate the role of TGF-alpha in epidermal growth and differentiation. Overexpression of TGF-alpha led to thicker epidermis and stunted hair growth, particularly in areas with naturally thick skin and low hair follicle density. This effect was linked to existing EGF receptor levels, with no evidence of TGF-alpha controlling EGFR expression. While no squamous cell carcinomas were found, benign papillomas were common in irritated or wounded areas. Additionally, adult skin sensitive to TGF-alpha showed signs similar to psoriasis, suggesting TGF-alpha's role in controlling epidermal thickness, papilloma formation, and possibly psoriasis, in conjunction with other factors.