Tumor volume at different time points.

<p>Tumor volume was showed as Mean±SD. Because a couple of animals were sacrificed at each time point, the number of the animals was 20, 18, 16, 14, 12 respectively at the five time points from baseline to 12 d. The tumor grew gradually with time. Initially, the tumor grew slowly but accelerated since 4 d. The mean tumor volume was significantly larger than that at previous time point at 8 d and 12 d. *P<0.05.