LLC tumor growth in G-CSF^−/− or G-CSF wt mice treated with PTX, PTX and G-CSF, or PTX and AMD3100 and the relative microvessel density, hypoxia, and perfusion. LLC cells in the quantity of 5 × 10⁵ cells were implanted in the flanks of (A) 8- to 10-week-old G-CSF^+/+ or G-CSF^−/− 129Sv/C57Bl/6 mice (n = 4-5 mice per group) or (B) 8- to 10-week-old C57Bl/6 which were treated with PTX, PTX and G-CSF, PTX and AMD3100. When tumors reached 200 mm³, treatment was initiated. Tumors were measured regularly using Vernier calipers, and tumor growth (volume) was plotted against number of days after tumor cell implantation. In a parallel experiment, C57Bl/6 mice bearing 500 mm³ LLC tumors (n = 4-5 mice per group) were treated with PTX or PTX in combination with either G-CSF or AMD3100. Tumors were removed 3 days later and evaluated for (C) microvessel density using CD31 immunostaining as a marker for endothelial cells (red; scale bar = 100 μm, 20×/0.50 NA); and hypoxia (green) and vessel perfusion (blue) using hypoxic probe and Hoechst as described in “Quantitation and visualization of tissue hypoxia, vessel perfusion, microcessel density, tumor cell proliferation, and apoptosis” (scale bars = 200 μm; 10×/0.30 NA). Quantification of (D) microvessel density, and (E) perfusion and hypoxia is provided.