Tamoxifen is A Na+-Antagonistic Inhibitor of Na+/K+-Transporting ATPase from Tumour and Normal Cells

Abstract
Tamoxifen is the most widely used antihormonal agent for the treatment of estrogen receptor-positive breast cancer.1 Tamoxifen controls breast cancer cell replication by blocking the binding of estrogen to the estrogen receptor and preventing estrogen-stimulated growth.2 It displaces the growth-promoting natural hormone estradiol-17β from its protein receptor and, consequently, its principal mode of action has been thought to be as an antiestrogen.2