PML and PIC 1 localization in AML. Dual immunofluorescence using PML monoclonal (left-hand panel) and PIC 1 polyclonal (center panel) antibodies. Images are fused in the right-hand panel; yellow signal denotes regions of PML/PIC 1 colocalization. (a) In APL cases associated with cryptic PML-RARα rearrangements, a microparticulate pattern of PML nuclear staining was associated with partial colocalization with PIC 1. In non-APL cases, eg, AML M4, shown in (b) and in t(11; 17)-associated APL (case no. 7; Table 1), shown in (c), PIC 1 was localized to the nuclear membrane and colocalized with PML within discrete nuclear bodies.