PML and acute promyelocytic leukemia: When cells enter senescence, HIRA and the other members of the HUCA complex, CABIN1 and UBN1, localizes in PML (ProMyelocytic Leukemia) nuclear bodies (PML-NBs) and this process is required for SAHF formation (Zhang et al., 2005; Ye et al., 2007; Banumathy et al., 2009; Rai et al., 2011).