MPO and polyp of colon: To analyze the relationship between MPO expression and CRC, the MPO expression data and detailed clinical characteristics of 478 CRC patients were downloaded from TCGA, including TNM stage, pathological stage, primary therapy outcome, sex, age, BMI, residual tumor, CEA level, perineural invasion, lymphatic invasion, history of colon polyps, presence of colon polyps, and mortality (Table 1).