Conversely, low ALDH2 activity can lead to aldehyde accumulation, and extrinsic aldehyde promoted reactive oxygen species (ROS) generation (Figure S5B) and concentration-dependent upregulation of TGF-β1 and β-Catenin in HCC cells (Figure 6A and 6B). The gene discussed is TGFB1; the disease is hepatocellular carcinoma.