NCIt definition : An endogenous metabolite formed during the O-methylation of the highly carcinogenic
catechol estrogen 4-hydroxyestradiol (4-OHE2) by catechol-O-methyltransferase (COMT),
with potential anti-proliferative activity. Even though the exact mechanism of action
through which 4-methoxyestradiol (4-MeE2) exerts its effect is not fully elucidated,
this chemical appears to have antiproliferative and apoptosis-inducing activities
in susceptible tumor cells.;