PML and leukemia: After karyogamic stage (Figure 3), the nuclei from Env-elicited syncytia accumulate promyelomonocytic leukemia (PML) nuclear bodies (PML-NBs).49 PML-NBs are defined by the presence of a protein called PML, a prominent onco-suppressor that is inactivated in some leukemias.50 PML proteins aggregate as a result of cellular and nuclear fusion and activate the ataxia telangiectasia mutated (ATM) kinase.