Accordingly, HIF-dependent signatures are upregulated in leukemic blasts of APL patients, and binding sites for the HIF-α heterodimerization partner HIF-1β are enriched in the promoters of genes preferentially expressed in APL blasts (Marstrand et al, 2010), thus indicating that activation of HIF factors is relevant to the pathophysiology of APL. The gene discussed is ARNT; the disease is acute promyelocytic leukemia.