SMAD3 and diabetic kidney disease: Furthermore, Ingenuity Pathway Analyses (IPA) of differentially expressed genes (upregulated by TGF-β in WT MMC but downregulated in KO5 MMC), to elucidate DKD related pathways, revealed inclusion of genes associated with kidney damages and fibrosis (Figure 2D) and inflammation (TNF in the center and SMAD3) (Figure 2E).