PML and acute promyelocytic leukemia: The absence of KDM3B could alter H3K9me1/me2 modification level companied with increasing of chromatin accessibility and inhibit ATRA-induced degradation of PML/RARα and, consequently, allow “easier” chromatin access and binding of PML/RARα protein in APL, which eventually leads to attenuate neutrophil differentiation of APL cells (Fig. 6b).