CRP and coronary artery disorder: 17 18 In contrast, Mendelian randomisation analyses using variants associated with circulating CRP in the interleukin-6 receptor gene region (IL6R) have shown inverse associations with CHD risk, suggesting that CRP might be protective against CHD. 19 20 However, genetic variants in the IL6R gene region primarily affect interleukin-6 receptor, which is upstream of CRP in the inflammatory response pathway21. Therefore, it is likely that interleukin-6 receptor rather than CRP is the causal risk factor for CHD (figure 2).