M1 macrophages promote the progression of DKD by secreting proinflammatory factors (IL-1β, IL-6, IL-12, IL-23, and TNF-α); M2 macrophages inhibit the development of DKD by secreting anti-inflammatory factors (IL-10 and TGF-β) (47, 48). This evidence concerns the gene TGFB1 and diabetic kidney disease.