TGFB1 and melanoma: Comparable levels of expression of SKI although there is almost complete lack of the SKI protein in normal melanocytes as compared to melanoma suggest that degradation of SKI protein in normal melanocytes is far more efficient than in malignant cells and involves an alternative, yet unidentified, TGF-β-independent mechanism of SKI degradation (or translation) and that this mechanism is deregulated in melanoma cells.