2-Methoxyestradiol-13C,d3 is the 13C- and deuterium labeled 2-Methoxyestradiol. 2-Methoxyestradiol (2-ME2), an orally active endogenous metabolite of 17β-estradiol (E2), is an apoptosis inducer and an angiogenesis inhibitor with potent antineoplastic activity. 2-Methoxyestradiol also destablize microtubules. 2-Methoxyestradio, also a potent superoxide dismutase (SOD) inhibitor and a ROS-generating agent, induces autophagy in the transformed cell line HEK293 and the cancer cell lines U87 and HeLa[1][2][3][4][5][6].