HIF1A and glioblastoma: High concentrations of HIF-1α have also been implicated in the progression and maintenance of a tumor stem cell phenotype in glioblastoma.53–55 HIF-1α drives the expression of FOXM1,39 which is thought to be involved in maintaining a stem cell-like phenotype in glioblastoma cells.40,43,45,46 BCAT1 knockdown in A11 cells and xenografts decreased HIF-1α expression and in cells decreased in FOXM1 expression, which resulted in a significantly lower potential of the cells to form tumor spheroids.