ARNT and Hepatic fibrosis: In light of previous studies which identified anti-fibrotic activity upon increased ARNT expression, we further demonstrate attenuated fibrosis upon monotherapy with the PP2A inhibitor LB100 in liver fibrosis model, and additive anti-fibrotic activities upon combination with pharmacological inducers of ARNT expression FK506 or GPI1046 in murine models of kidney fibrosis.