2-Methoxyestradiol (2ME2) is a natural metabolite of endogenous estrogen hormone 17β-estradiol in human and devoid of estrogenic activity. It is a drug that prevents the formation of new blood vessels that tumors need in order to grow (angiogenesis). It has undergone Phase 1 clinical trials against breast cancers. Preclinical models also suggest that 2ME2 could also be effective against inflammatory diseases such as rheumatoid arthritis. 2-Methoxyestradiol is an angiogenesis inhibitor, and has been shown to attack both tumor cells and their blood supply in preclinical testing. Presently, it is an investigational drug under various phases of clinical trials alone or in combination therapy. Its anticancer activity has been attributed to its antitubulin, antiangiogenic, pro-apoptotic and ROS induction properties. 2-Methoxyestradiol shows strong cytotoxic effect on estrogen dependent and independent cancerous cells, which is mainly due to disruption of microtubule process and p53 induced apoptosis through caspase, reactive oxygen species (ROS), superoxide dismutase (SOD) and nitric oxide synthase. 2-Methoxyestradiol inhibits tubulin polymerisation by binding to colchicine binding site of the tubulin and arrests cell cycle at G2/M-phase.