On the other hand, apoptosis could be induced in pancreatic carcinoma, breast tumor, and HCC cell lines by supplementing growth media with the on-pathway MSP product of ADI1GP oxidation, MTOB.[32-34] Furthermore, other upstream metabolites (e.g. MTA, SAM) also induce apoptosis.[24, 32, 34, 35] Ornithine decarboxylase 1 (ODC), an enzyme from the polyamine biosynthesis pathway, also inhibits tumor growth.[22, 36] As such, further investigations are needed to confirm that enhanced apoptosis and tumor inhibition with elevated ADI1GP expression levels are truly independent of metal binding. Here, ODC1 is linked to breast neoplasm.