IL6 and cystic fibrosis: The BALF results in our CF group were consistent with previous publications showing elevations in WBCs, predominately neutrophils, and increased levels of tumor necrosis factor (TNF)- α, interleukin (IL)-1β, IL-6, IL-8, granulocyte macrophage colony–stimulating factor (GM-CSF), and granulocyte colony– stimulating factor (GCSF) in airway secretions compared to controls [28].