We provide further evidence that sCTLA-4 contributes to immune regulation through T cell suppression with efficacy similar to that of the artificial soluble form of CTLA-4, CTLA4-Ig and selective blockade of sCTLA-4 also enhanced culture supernatant levels of both IFN-γ and IL-17A effector cytokines in anti-CD3 activated PBMC from volunteer melanoma patients. Here, CTLA4 is linked to melanoma.