IL10 and leprosy: Considering that: (i) HLA-G regulation includes stimulation of IL-10 expression, (ii) IL-10 is a key cytokine of Th2 cell-mediated immunity, associated with the pathogenesis of the severe forms of leprosy, (iii) HLA-G expression may be influenced by 3′ untranslated region (3′ UTR) variation sites by posttranscriptional mechanisms, in which many polymorphic sites have already been associated with the magnitude of HLA-G production, we aimed to study the polymorphic sites at the 3′ UTR of the HLA-G gene in leprosy and the possible association of polymorphisms with disease severity.