However, genetic variation in genes coding for PTPN22 (chromosome 1p13.2) and CTLA4 (chromosome 2q33.2), which have a higher-order role in immune regulation, have also been associated with T1D (Pociot and Lernmark, 2016) indicating that immunity might go astray on a superior level. Here, CTLA4 is linked to type 1 diabetes mellitus.