RARA and acute myeloid leukemia: Interestingly, a recent report in pediatric AML suggests a similar pattern of mutual exclusion; namely HOXA and HOXB down regulation in cases of RUNX1 or PML/RARA translocation or CEBPA double mutations, HOXA up regulation, HOXB down regulation in cases of MLL translocation and MYST up regulation, or HOXA and HOXB upregulation in patients with NPM1 mutation, and NUP98 translocations.