In initial MF skin lesions, an increased number of CD8 cytotoxic cells, in addition to FOXP3 regulatory T cells (Tregs), have been detected, which was attributed to an antitumor response promoted by dendritic cells [35–38]; on the contrary, the disease progression of MF was found to be associated with a remarkable decrease of normal Treg and cytotoxic T cells [39]. Here, FOXP3 is linked to mycosis fungoides.