Gene ontology (GO) analysis of metabolism-related genes suggested that upregulated genes in diabetic patients’ testes were enriched in “Apoptosis”, “NF-κB signaling”, “Interleukin-1 family signaling” as well as “The citric acid (TCA) cycle, and respiratory electron transport”, whereas genes annotated to “Lipid biosynthetic process”, “Glycerophospholipid metabolic process”, “Stress-activated MAPK cascade” and “Cellular response to insulin stimulus” were downregulated in T2DM compared to normal (Fig. 1e). Here, NFKB1 is linked to type 2 diabetes mellitus.