One of the main reasons is probably that the conflicting results, both pro- and anti-tumor effects, have been reported in other types of cancers, such as gastric, colorectal, and breast cancer.7,8,94 Another probable reason is that the increased level of IL-33 is just an epiphenomenon in response to the process of esophageal carcinogenesis, particularly in the case of ESCC. This evidence concerns the gene IL33 and neoplasm.