The impact of IL-34 in the pathogenesis of pulmonary fibrosis has been examined in a rat lung injury model, and it came to light that differentiation of M2Mφs was the dominant factor, and it can also induce an increase in the production of pro-fibrotic factors and promote collagen I production in hepatic stellate cells, indicating its involvement in the progression of liver fibrosis [167]. This evidence concerns the gene IL34 and Hepatic fibrosis.