PPARD and fatty liver disease: Although Terada and colleagues [58] discussed two possibilities in which one of them was that GW501516 might act as direct activator of PPARα in the absence of PPARδ, weight loss or hepatic steatosis was not observed in GW501516 treated PPARδ-KO mice (Figures 4(a) and 4(c)), demonstrating that activation of PPARα by GW501516 is not sufficient to induce these responses.