This finding is not unique as susceptibility alleles originating from resistant strains were found in studies of colon cancer [94] and L. major[95] susceptibility; a low-responder allele was identified in a strain exhibiting high response to IL-2 [96] or producing a high level of IFNγ [97], whereas a high responder allele was found in a strain producing low level of IL-4 [98]. This evidence concerns the gene IL2 and malignant colon neoplasm.