Since iron, 2-oxoglutarate and oxygen are necessary for the inactivation of HIF, it has been theorized that a lack of these cofactors could reduce the ability of hydroxylases in inactivating HIF. A recent study has shown that in cells with a high activation of HIF even in oxygenated environments was reversed by supplying the cells with ascorbate.[16] Thus, Vitamin C may be a potential treatment for HIF induced tumors.