(A) Immunohistochemical staining of CIAPIN1 in CRC tissues. (a) Normal colonic epithelium, strong staining (+++) was observed in the normal colon epithelial tissues, mainly in the epithelial cells, and no evidence of expression of CIAPIN1 was noted in cells of the germinal layer (×200). (b) Gland hyperplasia of colonic mucous membrane, strong staining (+++) of CIAPIN1 was observed in dysplasia colonic epithelial tissues, there was no significant difference in the expression level of CIAPIN1 protein between normal and dysplasia colon tissues (×200). (c) Well-differentiated adenocarcinoma of colon, intermediate staining (++) of CIAPIN1 in CRC tissues with high differentiation mainly in the epithelial tissues (×200). (d) Moderately differentiated adenocarcinoma of colon, weak staining (+) of CIAPIN1 in CRC tissues with moderately differentiation, mainly in the epithelial tissues (×200). (e) Poorly differentiated adenocarcinoma of colon, negative staining (-) of CIAPIN1 in CRC tissues with poorly differentiation (×200). (f) Negative control slides using anti-His as the primary antibody. (B) Overall survival of patients determined by the immunoreactivity of CIAPIN1. Overall survival analysis using the Kaplan-Meyer method revealed that CRC patients with relatively high expression of CIAPIN1 had a more favourable prognosis compared to those with low expression (P = 0.0002). (C) Receiver operating characteristic (ROC) curve for non-local recurrence (circles) within 5 years and survival (triangles) after 5 years.