An additional six candidate genes (FOXA1, DOK5, ISL1, WWC1, RRM2B and UBR5) were found in five QTL that were identified in human association studies of type-2 diabetes, Alzheimer’s and Huntington’s disease (Fig. 4)24, 25, 26, 27, 28. Here, ISL1 is linked to type 2 diabetes mellitus.