HOXA9 and leukemia: Given that genomic variation of HOXA9 including NUP98-HOXA9 fusion and gene amplification accounted for less than 2% of HOXA9 overexpression in AML cases (Xu et al., 2016; Gough et al., 2011; Nakamura et al., 1996), uncovering the upstream epigenetic and transcriptional regulators of HOXA9 in leukemia could advance the design of novel therapeutic interventions.