HIF1A and neoplasm: A higher mRNA expression of the HIF1 (but not HIF2) target genes, GLUT1 and HK2, was reported in VHL-mutated compared to SDHB-mutated adrenal medulla tissue (Fliedner et al. 2012), and VHL-mutated tumours demonstrate increased glycolysis in comparison to SDHx-derived PPGL (Favier et al. 2009).