PPI analysis demonstrated that hub genes were IFITM1, RTP4, ACSF2, GSTM2, GSTM1, ACOX2, COL4A6, ITGA2, AKR1B1, NPY, CFTR, GPX7, ALDH3A1, CRYZ, ALDH2, MAOB, GSTP1, GPX3, XAF1, and BST2, which might play important roles in DNA methylation in prostate cancer patients. The gene discussed is RTP4; the disease is prostate carcinoma.