IL4 and diffuse cutaneous Leishmaniasis: Furthermore, they have also found that the absence of IL-4 contributes to the overall good prognosis of LCL caused by L. major. IL-4 was expressed at low levels in localized cutaneous leishmaniasis (LCL) when compared to non-healing lesions of mucocutanoues cutaneous leishmaniasis (MCL) and diffuse cutaneous leishmaniasis (DCL).