HIF1A and central nervous system cancer: As illustrated in Figures 3D, E, hypoxia (1% O2) significantly induced HIF1A protein levels, especially in U251-MG and U87-MG cells; the expression of OR7E156P showed to be dramatically upregulated within glioma cells than that within HEB cells, more upregulated in U251-MG and U87-MG cells.