PDGFB and Hepatic fibrosis: We also found significant upregulation of caspase 1 (Casp1), a key inflammation mediator (26); Janus kinase 3 (Jak 3), a key controller of signal transduction after receptor activation by the common γ chain (27); and platelet-derived growth factor (Pdgfb), a key regulator of hepatic fibrosis (28).