Inhibition of tumor growth in vivo by dsRNA specific for EGFR. Transfected SPC-A1 cells (~1 × 106) were injected into the left flank area of the mice and tumor xenografts were allowed to grow to a size of approximately 10 mm × 10 mm. After mice were sacrificed, tumors were removed and weighed. (A) Tumor volumes measured by calipers every 2 days. (B) Tumor weight. Each column represented the mean of six mice, bars, SD.