CXCR4⁺ overexpressing WM cells with aggressive ability to disseminate to bone marrow, liver, and kidney in SCID/Bg mice as demonstrated by immunofluorescence imaging of GFP-tagged CXCR4⁺ WM cells. DAPI, 4′,6 diamidino-2-phenylindole; RFP, red fluorescent protein. Adapted from Figure 2D in the article by Roccaro et al that begins on page 4120.