Moreno et al. further confirmed the mechanisms of suppressing the biological activity of PGs by vitamin D. Calcitriol decreases the mRNA expression of the PGE2, inhibits the oncogene COX-2, and induces the expression of the putative tumor suppressor 15-PGDH in prostate cells, suggesting that calcitriol may play an important role in the chemoprevention of PCa [91]. Here, HPGD is linked to posterior cortical atrophy.