We select the differential genes from T2DM with |log2FC| ≥ 1.5 and take the intersection of the differential genes from IGT with |log2FC| ≥ 0 to obtain the Co-DEGs, namely, CFB, TSHR, VNN2, APOC1, CLDN2, SLPI, LCN2, CXCL17, FAIM2, REG3A. The gene discussed is CFB; the disease is type 2 diabetes mellitus.