HIF1A and colon carcinoma: Indeed, in addition to the studies demonstrating HIF-1α-dependent VEGF regulation, there is also work demonstrating HIF-1α-independent release of VEGF, as has been shown, for example, in human astrocytes exposed to pulsed electromagnetic fields [47], in colon carcinoma cells under normoxic conditions [48], or in astrocytes exposed to carbon monoxide [49].