Because the lung is a mucosal barrier organ with a unique immunologic environment, mechanisms of immunoregulation in lung cancer may differ from those of other malignancies. Consistent with this notion, we found that CD8+ T cells played a paradoxical role in facilitating, rather than ameliorating, the growth of multiple lung adenocarcinoma models. These included spontaneous, carcinogen-induced, and transplantable tumor cell line models. Specifically, we found that CD8+ T cells promoted homing...