Most of the earlier literature (Table 3) indicates that EGCG is the most potent growth inhibitor of cell lines from glioblastoma, melanoma and cancers of the breast, colon, lung, prostate (androgen-receptor-positive), pancreas, liver and mouth. EGCG prevents proliferation of DU145 cells by arresting the cell cycle at G 0 /G 1 -phase (19) . Gupta and others (26) have documented that G 0 /G 1 -phase arrest is independent of p53 mutation, and EGCG treatment of DU145 induces the cyclin kinase inhibitor WAF1/p21. These observations suggest that EGCG imposes a cell-cycle checkpoint (19) . However, our results showed that ECG may be more potent than EGCG for inhibition of primary and metastatic CaP and EOC cells (Fig. 4, Tables 1 and 2) . ECG significantly reduced cell proliferation (Table 1, Figs 2 and 3) and increased mean doubling time (Table 1, Fig. 4) .