Among these HATs, we found that the expression of GCN5 was selectively increased in the liver of two mouse models of obesity-associated type 2 diabetes—normal mice fed a high-fat diet (HFD) (Fig. 1a) and db/db mice (Fig. 1b,c)—compared with control mice. The gene discussed is KAT2B; the disease is obesity due to melanocortin 4 receptor deficiency.