Genetic variations, such as single nucleotide polymorphisms (SNPs) in the IL-6 gene promoter region (e.g., -174G/C and -572G/C), are associated with increased RA susceptibility and disease activity.32 In RA patients, IL-6 expression is not only elevated systemically but also markedly upregulated in synovial tissues compared to peripheral blood. The gene discussed is IL6; the disease is rheumatoid arthritis.