PML and acute promyelocytic leukemia: While our observation that UBE2L6 is induced only in ATRA‐sensitive NB4 APL cells could be explained by direct repression by PML‐RARα, we observe equivalent UBE2L6 expression levels in ATRA‐sensitive and ATRA‐resistant HL60 cells which do not carry the PML‐RARα oncoprotein.