Notably, the relevance of plasma S100A1 levels was illustrated at various levels: (1) by clustering lung cancer patients into groups with different responses to ICB treatment; (2) by establishing a potential strategy (GM-CSF as an immunostimulatory adjuvant) to prime tumor cells with high S100A1 expression to the ICB response; and (3) by revealing novel synergistic targets for cancer immunotherapy. Here, CSF2 is linked to lung cancer.