In an in vivo tumorigenicity study, Balb/c nude mice (4–6 weeks) of 18–22 gm were subjected to subcutaneous injection of Bcl-2-siRNA transfected human gallbladder carcinoma cells (GBC-SD) suspensions of 6 × 106 cells in 0.2 mL for experimental group and GBC-SD suspensions of 6 × 106 cells in 0.2 mL alone for control group into the left flank of the mice. The gene discussed is BCL2; the disease is gallbladder carcinoma.