Against this background of controversial data, the present study was designed to investigate the prognostic value of TNF-α, IL-1β, IL-6 and TGF-β1 plasma levels to predict RP and to evaluate the potential impact of a tumour-derived cytokine production on circulating plasma levels in patients irradiated for NSCLC. The gene discussed is IL6; the disease is non-small cell lung carcinoma.