GSTP1 and posterior cortical atrophy: We chose this 40 genes panel because some of the selected genes (GSTP1, TIMP3, RARB, CDKN2A, HIC, APC, CD44, RASSF1, CDH13, DAPK, BCL2, SFRP5, RUNX3) are already known to be frequently methylated in PCa [11, 12]: GSTP1 is the most widely studied and it is methylated in 70–80 % of cases [9].