The quantitative analysis showed that the antibody titers of G antigen 1 (GAGE1), rhophilin associated tail protein 1 (ROPN1), sperm protein associated with the nucleus, X-linked, family member A1 (SPANXA1), and protein kinase C zeta (PRKCZ) in the serum samples from PCa patients were higher than those from BPH patients, and melanoma antigen family B1 (MAGEB1) and PRKCZ were found to be highly expressed. The gene discussed is ROPN1; the disease is posterior cortical atrophy.