Then, we obtained seven hub genes: ADM, FFAR2, HLA-DQA1, ID3, OGFRL1, RRAGD, and TNF. These hub genes are not only associated with the expression of multiple immune cell types but also have a high accuracy in T1D diagnosis, with AUCs of 0.9375 (ADM), 0.9792 (TNF), 0.9688 (OGFRL1), 0.9271 (HLA-DQA1), 0.8958 (RRAGD), 0.8250 (ID3), and 0.7604 (FFAR2). This evidence concerns the gene RRAGD and type 1 diabetes mellitus.