Protein localization of PML and its fusion proteins in primary leukemia cells from patient #1. May-Giemsa (MG) staining (A) and IF staining (B) are shown. The primary leukemia cells from patient 1 were obtained at diagnosis and at the terminal stage (shown as 1 and 5, respectively, in Figure 1A) and were used in this assay. PML nuclear bodies can be observed in the cells at diagnosis (i and iii), but at the terminal stage, PML and its fusion proteins were observed in the cytoplasm showing a diffuse pattern (iv and vi).