Elevated expression of IL-22 was investigated in human colon cancer (CC). A: Expression of IL-22 in PBMCs (n = 40) and TILs (n = 82) from patients suffering from CC, as detected by real-time PCR (unpaired t-test). B: Average integrated optical density (IOD) was obtained by analyzing five fields for each slide evaluated by Image-Pro Plus software (version 5.0) for IHC staining of IL-22 in CC, UC and normal controls (unpaired t-test). C: Expression and distribution of IL-22 in normal colon tissues (n = 40), CC tumor tissues (indicated by arrows) (n = 82) and UC tissues (n = 40), as analyzed by IHC. D1: IL-22 expression in TILs (n = 32) and PBMCs (n = 32) by flow cytometry co-stained with antibody to CD3, D2. Comparison of IL-22 in TILs and corresponding PBMCs (paired t-test). ** represented P < 0.01 and * represented P < 0.05.