NR4A1 is highly expressed in type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM) mouse models, and the ablation of liver NR4A1 in T2DM db/db mice via adenoviral delivery of a dominant-negative NR4A1 inhibits the expression of key enzymes of gluconeogenesis in the liver and restores elevated glucose levels to near normal [73, 74]. Here, NR4A1 is linked to type 1 diabetes mellitus.