Consistently, the CC genotype of CYP27B1 is associated with poor response to interferon-α-based treatment of chronic hepatitis C in the present and in our previous study [18], as well as with the risk of bone disease or autoimmune disorders such as multiple sclerosis or type 1 diabetes [19], [20], [27], [29]. This evidence concerns the gene CYP27B1 and type 1 diabetes mellitus.