Judging from S100a9’s pro-inflammatory and pro-tumor functions in CAC regulation, neutralizing S100a9 antibody were administered to the AOM/DSS-induced CAC mice, and we observed that mice treated with anti-S100a9 antibody showed significantly reduced tumor incidence, growth, and infiltration of macrophages and neutrophils within tumors, which is similar to S100a9 null mice in the CAC model (31). This evidence concerns the gene S100A9 and neoplasm.