ODC1 and posterior cortical atrophy: These findings are in accord with those showing that androgen tightly regulates polyamine biosynthesis via control of ornithine decarboxylase (ODC1) and SAM-decarboxylase (AMD1) [21, 27], and magnetic resonance spectroscopy analyses of clinical samples have suggested spermine as a biomarker for the malignant behavior of PCa [28].