Another study in prostate cancer showed that piR-31470 forms a complex with piwi-like RNA-mediated gene silencing 4 (PIWIL4) and then recruits DNMT1, DNA methyltransferase 3α, and methyl-CpG binding domain protein 2 to initiate and maintain the hypermethylation and inactivation of glutathione S-transferase P1 (GSTP1) [175]. The gene discussed is PIWIL4; the disease is Familial prostate cancer.