As reported above, some cases of ICI-related rhinosinusitis are correlated with eosinophilic infiltration in sinus biopsies, suggesting an eosinophilic-driven inflammatory process, while ICIs may also trigger eosinophilic chronic rhinosinusitis, a subtype of sinus inflammation driven by IL-4, IL-5, and IL-13, cytokines that also contribute to peripheral eosinophilia [16]. Here, IL4 is linked to Increased total eosinophil count.