PASK and obesity due to melanocortin 4 receptor deficiency: However, our data confirm that PASK deficiency alters the expression of Ppargc1a and several TFs and nuclear receptors of this pathway: Nrf2, Ppara, and Pparg. All of these TFs were overexpressed under fasted conditions, and Ppargc1a and Pparg also under basal conditions in Pask−/− mice; suggesting that biogenesis may be stimulated in PASK-deficient mice and agree with the protection against obesity observed in these mice23,25.