EPAS1 and leukemia: In AML, recent work has described HIF1α and HIF2α as either tumor promoters (Wang et al, 2011; Matsunaga et al, 2012; Rouault‐Pierre et al, 2013; Coltella et al, 2014; Forristal et al, 2015; Gao et al, 2015; Migliavacca et al, 2016) or tumor suppressors (Velasco‐Hernandez et al, 2014, 2019; Vukovic et al, 2015), a distinction that may be dictated by molecular specificities of leukemia subtypes, or different outputs of HIFs activity in normal hematopoietic progenitors versus leukemic cells (Magliulo & Bernardi, 2018).