PFKFB4 and cancer: Notably, silencing of PFKFB4 in other cancer cell lines cultivated under hypoxic conditions, such as DU145 (prostate) and MDA-MB-321 (breast), also caused a reduction of HIF-1α protein levels (Fig. S5K), suggesting that PFKFB4 could be important for the regulation of HIF-1α in additional cancer contexts to glioblastoma.