Of these 25 genes 8 (CTLA4, ICOS, CCR5, BACH2, IL2RA, RASGRP1, CLEC16A and PTPN2) have been shown to be significantly associated with T1D previously [32] while our analysis has identified a further 17 new candidate genes that may be disrupted in a Treg in T1D. Here, ICOS is linked to type 1 diabetes mellitus.