Although PIK3C3/PIK3R4 mutation and PIK3C3 gene amplification are infrequent events in prostate cancer (<1% of cases), PIK3R4 high-level gene amplification is observed in up to 6.5% of cases and could potentially facilitate prostate cancer growth (Tables S1–S3). This evidence concerns the gene PIK3C3 and Familial prostate cancer.