PHGDH and breast cancer: In contrast to the published results of breast cancer cells41 the hypoxia-induced upregulation of SHMT2 was only affected by a double gene-suppression of HIF-1α and HIF-2α in GBM cells whereas a single HIF-1α or HIF-2α gene-suppression as well as a double gene-suppression of HIF-1α and HIF-2α did not prevent induction of PHGDH under hypoxia (Suppl.