The expression of RAB4A was significantly decreased in primary prostate cancer when compared to PIN tissue (P ≤ 0.05; Figure 1) and there was a significant reduction of RAB4A expression in metastatic prostate tissue when compared to both non-malignant prostate cancer (P ≤ 0.01) and PIN tissue (P ≤ 0.0001; Figure 1). This evidence concerns the gene RAB4A and Familial prostate cancer.