SMAD4 and liver dysplastic nodule: Ma et al. showed that miR-130b is related to fibrosis in DN, and its overexpression can not only promote the mRNA and protein expressions of collagen types I and IV and fibronectin but also increase its downstream signal TGF-β1, t-Smad2/3, P‐SMAD-2/3, and SMAD-4 expressions, thus implying a profibrotic role of miR-130b in DN and its strong correlation with the canonical TGF-β/SMAD-2/3 signaling pathway (Ma et al., 2019).