IL6 and cancer: Also, we observed a common trend showing a significant correlation between median serum IL-6 and increasing cancer stages [21, 24, 26, 67, 74, 79, 82, 88, 91, 93, 95, 96, 98, 102, 106, 122, 123], which indicate that IL-6 may be a marker for a more severe type of cancer.