EGFR and breast cancer: In one of them [65], the oxygen sensor hypoxia-inducible factor prolyl hydroxylase 2 (PHD2), which is thought to be the principal HIF-1α regulator, has been found to correlate with EGFR in samples from breast cancer patients positively, thus showing a direct crosstalk between PHD2 and EGFR-mediated tumorigenesis in breast cancer for the first time.