Figure 1: Therapeutic targets of HO-1 during pathogenesis of metabolic diseases. Metabolic diseases, such as CVD, T2D, and obesity, frequently arise from defects among coordinated actions of multiple tissues. Cells in a tissue may be exposed to oxidative stress generated mainly by mitochondria, inflammatory stress initiated probably by saturated FA-TLR4 interaction, and ER stress triggered by inflammatory and oxidative stresses, and these stresses, when prolonged, may amplify and integrate with each other. The integration of advanced stresses may cause one or more of metabolic diseases. HO-1 expression may reduce oxidative stress, inflammatory stress, and ER stress, thereby exerting therapeutic actions.