Furthermore, the links between the immunoregulatory genes are likely underestimated in T1DM since, for example, Foxp3 loss-of-function mutations in humans cause the genetic disease immunodysregulation, polyendocrinopathy, enteropathy, X-linked syndrome (IPEX), which is a severe, typically fatal disease of mainly endocrine tissues that afflicts teenage boys (49, 50). Here, FOXP3 is linked to type 1 diabetes mellitus.