PLK1 and posterior cortical atrophy: Plk1 is overexpressed in PCa and linked to higher tumor grades, suggesting that Plk1 is involved in tumorigenesis and progression of PCa.[10] DNA methyltransferase 3A (DNMT3a), which catalyzes DNA methylation of promoters of genes, is also elevated in PCa.[11] Increased promoter methylation results in gene silencing of tumor suppressors.