While Prm1 (regulates TPα mRNA expression) was found to lie within a hypomethylated region in the benign/BPH and PIA lesions (β value ≈ 0.2), with little variation between individuals, methylation of Prm1 increased significantly in pre-invasive HGPIN tissues and primary and metastatic lesions (P = 0.0002, ANOVA). Here, PRM1 is linked to benign prostatic hyperplasia.