Infiltrating macrophages can release lysosomal enzymes, nitric oxide, reactive oxygen species, transforming growth factor-beta, vascular endothelial growth factor and cytokines such as TNF-α, interleukin-1 and interferon (IFN)-γ [32], which could play a pivotal role in the development and progression of DN. This evidence concerns the gene TNF and liver dysplastic nodule.