HIF1A and leukemia: Moreover, the authors also showed that high dose ascorbate markedly inhibited the expression of HIF-1α in leukemic cells by blocking the transcriptional activation of NF-kB, constitutively upregulated in many types of leukemia and associated with leukemic progression (Braun et al., 2006; Packham, 2008; Reikvam et al., 2009).