Proline can be metabolized by proline oxidase to generate reactive oxygen species as signaling molecules for epigenetic reprogramming, which regulates the redox homeostasis of cancer cells.11,49 It was recently shown that metabolic flux can cause changes in cancer cell adhesion and metastatic transformation.50 Future studies should focus on the relationship of the metabolome with the adhesome-degradome network in terms of driving breast cancer metastases. Here, PRODH is linked to breast cancer.