DUSP9 and Insulin resistance: However, in a stress-induced in vitro model of insulin resistance and following adenoviral-mediated overexpression of DUSP9/MKP-4 in the livers of genetically obese (ob/ob) mice Emanuelli et al. reported that DUSP9/MKP-4 expression improved glucose intolerance, decreased the expression of gluconeogenic genes and reduced hepatic steatosis [180].