IL6 and rheumatoid arthritis: Mendelian randomization, which is deemed as more similar to randomized clinical trials due to the Mendel 2nd law, has been introduced as a viable technique to overcome drawbacks of observational epidemiological studies and obtain robust causal estimates.[10] Therefore, the Mendelian approach was employed to evaluate the causal relevance of IL-6 with RA risk, with focus on the IL-6 -174G/C variant.