Reduction in the number of formed spheroids (optical microscope) generated by 1x106 disaggregated cells (cultured in stem cell conditioned media and low-adhesion plates) obtained from CXCR4+ M5 subcutaneous tumors, 24h after 100µg T22-GFP-H6-FdU intravenous doses, for 2 consecutive days, as compared to Buffer-treated or free oligo-FdU-treated mice. (N=8; 2 mice/group; 4 plates/mouse). (Scale bar, 100µm). 