S100A9 and cancer: In the immune system, the monomeric of S100A8 and S100A9 protein are primarily expressed in neutrophils and monocytes, playing critical roles in modulating inflammatory responses and inflammation-associated diseases.35,36 Conversely, in squamous cell carcinomas, the monomeric of S100A8 and S100A9 protein exhibit an opposite prognostic association.37–39 In this study, we found that S100A8/A9 complex are predominantly expressed by squamous epithelium derived cancer cell (Supplementary Fig. 7a).