Considering the findings from animal models of leishmaniasis (69–76), it is reasonable to propose that individuals harboring the haplotype associated with susceptibility to the development of Lg-Cl might display increased expression of TH2LCRR. This heightened expression could potentially result in sustained polarization of Th2 cells and the subsequent release of IL-4 and IL-13. This evidence concerns the gene IL4 and leishmaniasis.