IL22 and liver cancer: The overexpression of IL-22 in HepG2 cells, a human liver cancer cell line, constitutively activates STAT3 and induces the expression of antiapoptotic proteins, including B-cell lymphoma (Bcl)-2, Bcl-xL, and myeloid cell leukemia-1, and mitogenic proteins, such as c-myc, cyclin D1, and cyclin dependent kinase 4 [135].