S100A9 and neoplasm: Responses to ICB have been associated with TIICs, an increase in tumor-infiltrating PD-1hiCD8+T cells, LAG3+CD8+T cells and monocytes/macrophages in tumor as well as S100A9+CD14+monocytes in the peripheral blood of patients exhibiting suboptimal responses to anti-PD-1 therapy (48–50).