IL6 and cancer: The median level of IL-6 increased proportionally with the stage of the cancer (the median level of IL-6 in stage I 7.36 ± 5.52 pg/ml, stage II 7.66 ± 2.24 pg/ml, stage III 11.87 ± 14.90 pg/ml and stage IV 13.92 ± 10.76 pg/ml), and this difference was statistically significant (P < 0.001).