RA patients with IL-6 rs1800795-GG genotype had a higher risk of failure in therapeutic response to leflunomide when compared to patients with -GC (55), which was contrary to other observations of noninfluence of the rs1800795-GC IL-6 gene polymorphism on response to leflunomide that used different measures for defining response to therapy (54, 75). Here, IL6 is linked to rheumatoid arthritis.