Co-localization (yellow merged) of the T22-GFP-H6-FdU (green) and the CXCR4 receptor (red) and release of T22-GFP-H6-FdU into the cytosol in CXCR4+ tumor cells 5h after a 100ug dose of nanoconjugate, as measured by dual anti-GFP/anti-CXCR4 immunofluorescence (IF). DAPI (blue nuclear staining). Fluorescence emission was measured in the green and red channels using the Image J software and expressed as mean Area (A)±s.e.m (µm2) (N=10, 2 tumor fields x 5 mice; 200X). Note the significant (P=0.003) increase in the area occupied by the green dots (nanoconjugate realeased to the cell cytosol) in T22-GFP-H6-FdU-treated tumors, compared to free oligo-FdU-treated control tissues. Scale bar, 50 µm. 