Moreover, changes to MEIS/HOXB13 transcriptional regulation or interaction by HOXB13 mutations could enable MEIS proteins to pair with HOXA9 or HOXA10 to drive oncogenesis and progression, such as in leukemia or ovarian cancer (Kelly et al., 2011; Kroon et al., 1998). Here, HOXA9 is linked to leukemia.