We bought 4‐week‐old male BALB/c nude mice from Beijing Vital River Laboratory Animal Technology Co., Ltd. The mice were randomly divided into 2 groups based on a previously described standard protocol. 1 × 106 SW480‐Vector or SW480‐ATGL cells were injected into the inguinal folds of mice, respectively (n = 6 in each group). And a nude mouse injected with SW480‐Vector cells did not form tumour. We measured the tumour volume with an external calliper and calculated its results by the following formula: Volume = length × width2⁄2. The mice were killed at 27 days after injection. Then, tumours were dissected, weighed, photographed and stored at −80°C for further researches.