IL6 and colorectal cancer: Furthermore, patients with COPD with frequent exacerbations were reported to have high levels of inflammatory markers, such as CRP [47], fibrinogen [47], IL-6 [48], soluble tumor necrosis factor-α receptors [37,49,50], and osteoprotegrin [37], which have been shown to be associated with the survival of patients with colorectal cancer [39,40,41,42,51,52,53,54].