IL6 and lung cancer: Tumor (CEA, CYFRA 21-1, and NSE), inflammatory markers (IL-6, TNF-α, SAA1, CRP, MMP-2, and MMP-9), and metabolic markers (glucose, lactate, and LDH) were measured in the sera and plasmas of 112 lung cancer patients, who were classified into four groups based on subtype and seven groups based on stage.