Full-length HIF-3α variants, such as HIF-3α1 and HIF-3α9, have transactivation activity and can activate a large number of target genes in response to hypoxia whereas the short isoform HIF-3α4 has been shown to act as a dominant-negative regulator of HIF-1/2α (Makino et al., 2001; Maynard et al., 2005; Heikkilä et al., 2011) that is able to impair proliferation and angiogenesis in hypervascular meningioma cells (Ando et al., 2013). Here, HIF1A is linked to meningioma.