Ikezumi et al. [20] reported that in IgA nephropathy, M1-type activated macrophages are involved in formation of acute active lesions such as intratubular proliferation of the glomerulus or cellular crescent form and M2-type activated macrophages are involved in formation of chronic lesions such as glomerular sclerosis or interstitial fibrous change through syntheses of fibrous promotion factors such as TGF-β or CTGF. The gene discussed is CCN2; the disease is IgA glomerulonephritis.