Malignant tumors can enhance their ability to survive and spread by suppressing antitumor immune cells in their vicinity, but a study led by researchers at Weill Cornell Medicine and NewYork-Presbyterian has uncovered a new way to counter this immunosuppressive effect. In the study, published on September 20, 2021, in  Nature Cancer , the researchers identified a set of anti-immunosuppressive factors that can be secreted by cells called club cells that line airways in the lungs. They showed in a mouse model of lung cancer that these club cell factors inhibit highly potent immunosuppressive cells called myeloid-derived suppressor cells (MDSCs), which tumors often recruit to help them evade antitumor immune responses. The inhibition of the MDSCs led to an increase in the number of antitumor T cells at the tumor site, and greatly improved the effectiveness of FDA approved PD1 immunotherapy. “These club cell-secreted factors are able to nullify immune suppressor cells that other...