COMT and leiomyoma: In fact, it was demonstrated that green tea extract and its active component, the epigallocatechin gallate (EGCG), in vitro inhibits proliferation and induce apoptosis in Eker rat leiomyoma tumor 3 cells and likewise in vivo exerts an inhibitory effect on human myoma cell lines [61,62], modulating catechol-O-methyltransferase (COMT) expression and enzyme activity [63].