S100A9 and colorectal carcinoma: Hu’s research pointed out that Fusobacterium nucleatum (Fn) regulates the ratio of M1 to M2 macrophages through the activation of TLR4/NF-κb/s100A9 signaling, and promotes M2-type macrophage polarization, which contributes to TME re-editing and stimulates CRC metastasis (42).