IL6 and central nervous system cancer: On the other hand, our results showed that circulating IL‐6 [HR 1.10 (95% CI: 1.05‐1.16; P = .000)] and CRP [HR 2.02 (95% CI: 1.52‐2.68; P = .000)] levels were highly correlated with a poor overall survival (OS) rate in glioma patients.