IL4 and neoplasm: Recent studies have shown that eosinophils can infiltrate tumors and release granule proteins, such as eosinophil cationic protein and eosinophil peroxidase, as well as cytokines, including TNF-α, IL-4, and IL-13, which can induce direct tumor cell cytotoxicity and promote CD8+ T-cell and dendritic cell activation [15,16,17].