The prognostic relevance of tumour-infiltrating plasma cells and immunoglobulin kappa C indicates an important role of the humoral immune response in non-small cell lung cancer

► IGKC gene and protein expression in human non-small cell lung cancer is associated with prognosis. ► IGKC is expressed in stroma-infiltrating plasma cells. ► The humoral immune response plays an important role in non-small cell lung cancer.