The results showed that p27 gene was down-regulated in ESCC (SMD = -0.45, 95% CI = -0.74∼-0.16, P = 0.002; I2 = 50.6%, P = 0.04; Figure 9A) and up-regulated in CRC (SMD = 59, 95% CI = 0.34∼0.83, P < 0.0001; I2 = 79.2%, P < 0.0001; Figure 9B). This evidence concerns the gene CDKN1B and esophageal squamous cell carcinoma.