CTLA4 and melanoma: Moreover, we detected increased granzyme B-, perforin-, Fas-, and CTLA-4 mRNA levels in α-MSH stimulated CD8+ T cells form melanoma patients with skin type 2/3 compared to PBS treated cells from the same patient (Figure 7B) indicating that also in human CD8+ T cells α-MSH up-regulated the expression of cytotoxic genes.