CSF2 and neoplasm: Neutrophils have been reported to promote tumor progression through immunosuppressive and pro-inflammatory mechanisms, whereas eosinophils have been shown to mediate antitumor immunity by recruiting cytotoxic T cells and secreting cytokines such as interleukin-5 and granulocyte-macrophage colony-stimulating factor [20,21]. Therefore, a low NER may reflect an immune environment that is not only more prone to irAE development but also potentially indicative of a favorable response to ICIs.