Proliferating cell nuclear antigen (PCNA) inhibitor. Directly binds PCNA trimers (Kd = 0.41 μM), reduces chromatin-associated PCNA in cells, inhibits cell growth through induction of S and G2M arrest, and attenuates DNA replication in cells. Inhibits growth of a range of tumor cell lines in vitro with IC50 values in the nanomolar to low micromolar range. Inhibits growth of prostate tumor xenografts in mice. Purity 98%. MW (observed): 310.37