COL18A1 and posterior cortical atrophy: Three proteins that we found with increased abundance in PCa, namely Non-secretory ribonuclease (RNASE2), Actin gamma-enteric smooth muscle (ACTG2), and Collagen alpha-1(XVIII) chain (COL18A1), may be of special interest for further investigation as these proteins have been found also increased in PCa tissues but are not detected in normal prostate tissue, according to The Human Protein Atlas.