At 7 weeks post implantation PROS1 knockdown tumors had significantly smaller tumor volumes with 66% smaller tumors for shPS1 cells (27 mm3 mean tumor volume, P < 0.03), and 96.2% smaller tumors for shPS2 (3 mm3 mean tumor volume, P < 0.001), compared to shEV (78 mm3 mean tumor volume) (Figure 4A, 4B). This evidence concerns the gene PROS1 and neoplasm.