Investigating 20 non-HLA SNPs for development of IA, progression from IA to T1D, and/or development of T1D, Steck et al. found PTPN22 (rs2476601) associated with development of IA, but not progression from IA to T1D, and CTLA4 (rs231775) associated with progression from IA to T1D, but not development of IA [9]. This evidence concerns the gene CTLA4 and type 1 diabetes mellitus.