Anti-CD28/CD49d were used in all the culture of mononuclear cells as costimulatory molecules and to test whether Tregs influence development of leprosy reactions, we analyzed CD4+ and CD8+ Treg cells, defined as CD25+Foxp3+, in multibacillary patients, T1R, T2R and HV. This evidence concerns the gene FOXP3 and leprosy.