S100A9 and breast carcinoma: In breast carcinoma, multiple S100 proteins are dysregulated, including S100A2, S100A4, S100A6‐9, and S100A11.[60] Among them, S100A8 and S100A9 can recruit MDSCs to maintain an immune suppression state in the TME,[12] indicating the key roles of S100 family proteins in modulating the TME.