NUDT21 and HIV-1 infection: HIV-1 infection alters the immunofluorescence microscopy patterns of CPSF5 and CPSF6 from a mixture of diffuse and granular nuclear staining to easily recognizable large condensates or puncta-like structures (2, 4, 5, 8) that colocalize with the nuclear speckle marker SC35, implying that HIV-1 infection triggers the translocation of CPSF5 and CPSF6 to bona fide nuclear speckles (2, 4, 5, 24).