A large-scale gene expression comparison between prostate cancer and normal tissue (32) showed Plexin-B1 expression was altered in 30% of patients with prostate cancer (z-score = ±2) and Plexin-B1 expression downregulation was three times more common (22.67%) in prostate cancer than its increase (7.33%). This evidence concerns the gene PLXNB1 and Familial prostate cancer.