In human colon and ovarian cancer cells, under non-hypoxic conditions, prolyl-1-4 hydroxylase proteins (PHDs) hydroxylate HIF-1α, which then binds von-Hippel-Lindau proteins, causing proteasomal degradation of HIF-1α (Huang et al., 1998; Semenza, 2000). Here, HIF1A is linked to ovarian cancer.