INS and hepatocellular carcinoma: MKP-2 has been shown to repress gluconeogenesis by dephosphorylation of P38 in hepatoma cells [35]; MKP-4 has been demonstrated to impair insulin-stimulated glucose uptake in 3T3-L1 adipocytes [36]; and the prototype dual specificity phosphatase MKP-1 was shown to play a role in the development of diet-induced obesity [37].