PRODH and cancer: In pursuing N-propargylglycine (N-PPG) as a unique suicide inhibitor of mitochondrial proline dehydrogenase (Prodh) and potential anticancer therapeutic, we observed that, in both human cancer cells and normal mouse tissues, its irreversible inhibition and structural distortion of Prodh protein induces UPRmt and thereby activates mitohormesis, a property independent of N-PPG’s anticancer activity but consistent with its lack of any obvious host toxicity when administered orally for 9 days at 50 mg/kg (Scott et al., 2019; Scott et al., 2021).