IL-22 enhances tumor proliferation and anti-apoptosis ability by activating STAT3 signaling in vitro. A: Schematic diagram of experimental design. B1-B6: Immunofluorescence staining of BrdU in green and DAPI in blue, reflecting cell proliferation in each group detected by fluorescence microscopy (×200). B7: Immunofluorescense staining with non-specific antibody control (NC) (×200). B8: Comparison of cell proliferation in each group (the independent co-cultures experiments were repeated in triplicate) (unpaired t-test). C1: Analysis of apoptosis of Hct-116 cells induced by peroxide in each group by flow cytometry, C2: Comparison of apoptosis in each group (the independent co-cultures experiments were repeated in triplicate) (unpaired t-test). D. Western-blot detection of IL-22, p-STAT3 (S727), total STAT3, Bcl-XL, Bcl-2, and CyclinD1 expression, all normalized to the β-actin. *p <0.05; **p < 0.01.