To identify the nuclear dots that contain EDC4 when the protein is forced to enter the nucleus, HEp-2 cells were transfected with a plasmid encoding NLS-EDC4 and cells were stained with anti-EDC4 antibodies and rabbit antiserum directed against the Sp100 protein in promyelocytic leukemia (PML) nuclear bodies. This evidence concerns the gene PML and acute promyelocytic leukemia.