HIF1A and neoplasm: We have observed that clincopathological measures of a tumour's biological aggression are associated with overexpression of CYGB and, in parallel, the overexpression of HIF1A. However, we have also observed that, not only does substantial promoter methylation have an overriding effect of CYGB downregulation irrespective of hypoxia, but that CYGB upregulation in cell lines in response to hypoxia may be less dependent on alterations in CYGB promoter methylation status.