Deletion of NNMT in the livers of C57BL6/J mice lowers fasting plasma glucose levels.218 The histone methyltransferase SETDB2-associated pathway IFN-β-SETDB2-H3K9me3 is dysfunctional in diabetes and induces nuclear factor kappa B (NF-κB)-mediated inflammation.219 The lack of histone methyltransferase G9a suppresses CD36 and M1 macrophage genes in type 2 diabetic patients.220 PRMT1 plays an essential role in maintaining mature β-cell identity.35 Deficiency of PRMT5 impairs glucose tolerance and glucose-stimulated insulin secretion in a mouse model. The gene discussed is NNMT; the disease is type 2 diabetes mellitus.