EDN1 and freckles: In UVB-melanosis [4–11] and in solar lentigo [12,13], EDN1 and membrane-bound SCF (mSCF) are up-regulated at the production and/or secretion levels due to the UVB-stimulated release of interleukin (IL)-1 and the UV-independent secretion of tumor necrosis factor α (TNFα), respectively.