Recent studies suggest that macrophages switched to the M1 phenotype exert pro-inflammatory as well as pro-fibrogenic roles in the pathogenesis of liver fibrosis [46,47,48], while macrophages polarized to M2 phenotype responding to the stimulation of IL-4 or IL-13 attenuate the progression of liver fibrosis [49,50]. The gene discussed is IL13; the disease is Hepatic fibrosis.