Furthermore, TGF-β1 signalling pathways are negatively regulated by SMAD7 activation [169], and decreased levels of SMAD7 in the diabetic cells compared to those in the controls led to a delayed response of the lung to the diabetes, and also confirmed the activation of the TGF-β1 signalling pathway in the lung [159]. The gene discussed is TGFB1; the disease is diabetes mellitus.