HOXA9 and acute leukemia: To date, most known HOXA9 regulator proteins are epigenetic modifiers, and little is known about which DNA-binding transcription factors are involved in directly regulating HOXA9 expression in acute leukemia (Godfrey et al., 2017; Daigle et al., 2011; Yu et al., 2012; Shi et al., 2012).