Results revealed that higher Bmi-1 interference rate was found by Ad-Bmi-1i in cancer cells with higher Bmi-1 expression, while lower Bmi-1 interference rate was found in GES-1 cells and gastric cancer cells with lower Bmi-1 expression, which means that the higher Bmi-1 silencing efficiency was obtained in gastric cancer cells with higher Bmi-1 expression (Figure 1C), suggesting that Ad-Bmi-1i selectively expressed and exerted silencing effects in cancer cells with higher Bmi-1 expression. Here, BMI1 is linked to cancer.