Tetrathiomolybdate (TM) treatment significantly inhibits HNSCC tumor growth and tumor angiogenesis. OSCC-3 and EC-Bcl-2 or EC-VC cells were mixed with 100 μl of Matrigel and injected in the flanks of SCID mice. Tumor volume measurements began on day 3 and continued twice a week until the end of the study. Length and width were measured using a digital caliper and tumor volumes were calculated using the formula, volume (mm3) = L × W2/2 (length L, mm; width W, mm). A; tumor progression curves for different experimental groups: OSCC-3 plus endothelial cells transduced with vector alone (EC-VC); OSCC-3 plus endothelial cells transduced with vector alone and treated with TM (EC-VC+TM); OSCC-3 plus endothelial cells transduced with Bcl-2 (EC-Bcl-2); OSCC-3 plus endothelial cells transduced with Bcl-2 and treated with TM (EC-Bcl-2+TM). B; tumor weights at the end of the study. C-D; Paraffin embedded tumor sections were stained for tumor blood vessels using anti-human von Willebrand Factor antibodies. Microvessel density in the tumor samples was calculated by counting 5 random fields (x 200). *, represents a significant difference (p < 0.05) as compared to the control group.