In cutaneous leishmaniasis, the only existing data is a recent report on which the addition of an anti-IL-10 mAb abrogated the in vitro modulatory effect of intralesional CD4+CD25+Foxp3+ Treg cells and promoted an increase in IFN-γ production by effector T cells from L. guyanensis infected individuals [2]. This evidence concerns the gene IFNG and cutaneous leishmaniasis.