Down-regulating AQP5 expression appears to inhibit tumor growth in athymic mice. Tumor growth was observed within 30 days since visible tumor observed. Lentivirus solution or PBS buffer were subcutaneously injected when the average diameter of tumors researched approximately 4 to 6 mm. No tumor growth was observed in mice injected with PBS instead of 3AO cells. Means and standard deviations of tumor volume were calculated from multiple observations in three groups of mice. Statistically significant differences were noted between mice received Lenti-AQP5-shRNA virus injection and mice injected with Lenti-NC virus or PBS buffer (t test, p < 0.01). n = 5 per group.