The role of IL-9 in the tumor microenvironment and its effects on macrophages remains unclear. Here, the authors show that IL-9 promotes the expansion of pulmonary macrophages and that targeting the IL-9R/arginase 1 axis restricts tumor growth, thus identifying this cytokine pathway as a potential therapeutic target.
- Yongyao Fu
- Abigail Pajulas
- Mark H. Kaplan
