Green tea is widely consumed in Japan and China and its polyphenolic components have a chemopreventive effect against cancer in vitro and in vivo (39) . A cup of green tea contains 100-150 mg catechins, of which 8% are EC, 15% are EGC, 15% are ECG and 50% are EGCG (40) . Although numerous investigations have shown the role of EGCG in cancer chemoprevention, only a few studies have attempted to compare the relative antitumor efficacy of all four catechins (Table 3) . When we used a systematic approach to assess the effect of various catechins on cell lines derived from gender-based cancers, we found that each catechin's antitumor activity depended on the type of tumor. EGCG was not always the most potent chemopreventive agent.