IL6 and cancer: Elevated levels of all three markers were associated with risk of cancer within 3 months: CRP (odds ratio (OR) 4.41, 95% confidence interval (CI) 2.86–6.81), IL‐6 (OR = 2.89, 1.91–4.37) and YKL‐40 (OR = 2.42, 1.59–3.66).