ALKBH5 and breast cancer: Because hypoxia-induced ALKBH5 expression is HIF-dependent in breast cancer cell lines [13, 14] and human breast cancers are hypoxic, with a median pO2 of 10 mm Hg (∼1.5% O2) [30], we hypothesized that ALKBH5 and HIF-1α expression should be correlated in breast cancer tissue.