Induced tumor cell apoptosis: EGCG triggered programmed cell death in NPC, correlating with suppression of SIRT1 and reactivation of p53 tumor suppressor function. The result is potent anti-tumor activity in vitro, indicating EGCG can target cancer cell survival pathways (like SIRT1) to overcome growth and survival advantages of tumor cells. This evidence concerns the gene SIRT1 and nasopharyngeal carcinoma.