The MN patch induced epidermal hyperplasia and marked expression of heparin-binding epidermal growth factor-like growth factor mRNA and protein corresponding to ATRA activity in the skin of HR-1 hairless mice.
Finally, heparin-binding EGF-like growth factor (HB-EGF), known to induce epidermal hyperplasia and itself overexpressed in psoriasis, was identified as a direct target gene of PPARdelta.