CNR2 and Familial prostate cancer: Similarly, 2-day treatment of both prostate cancer cell lines with the CB2-selective agonist GW-405833 (10 μM) resulted in 68.33 ± 3.8 and 55 ± 12.5% downregulation of CBRs expressed in PC-3 and DU-145 cells, respectively (Figure 6A,B).