FOXP3 and uveal melanoma: Though there were no significant differences in the percentage of CD4+ and CD8+ T cells between uveal melanoma patients and healthy blood donors, patients tended to have a lower fraction of cytotoxic CD8+ T cells and a higher fraction of helper CD4+ T cells, in particular of a regulatory T cell (Treg) phenotype as indicated by an abundance of CD4+ T cells with a high expression of Foxp3.