In rapidly growing cancer cells, the surrounding vasculature becomes inadequate with depleted oxygen levels in tissues; as a results, cytochrome oxidase consumes nearly all available oxygen rendering non-mitochondrial compartments essentially anoxic leading to decreased hydroxylase activity [41], and induces stabilization and transcriptional activation of HIF-1α protein, the regulatory member of HIF-1 complex. Here, HIF1A is linked to cancer.