Meanwhile, the serum levels of XPNPEP2 in Pca patients were measured to evaluate the association between serum XPNPEP2 levels and patient clinical and pathologic characteristics, including the PSA value, pathologic Gleason score, extracapsular extension, seminal vesicle invasion and lymph node metastasis. The gene discussed is XPNPEP2; the disease is posterior cortical atrophy.