To determine the role of PAX2 on EN2 expression in prostate cancer, PC3 and LNCaP cells were treated for 3 days with a pool of siRNA specifically targeted against PAX2. We previously demonstrated that siRNA knockdown of PAX2 expression occurs as early as 2 days in the prostate cancer cell lines (Gibson et al. 2007). This evidence concerns the gene PAX2 and Familial prostate cancer.