Fifteen articles examined the association of the IL-6 -174G/C variant with RA risk,[24–38] and 5 articles studied circulating IL-6 changes across -174G/C genotypes.[19,35,39–41] The publication years ranged from 2000 to 2014, and the total sample size ranged from 32[40] to 1550.[27]. Here, IL6 is linked to rheumatoid arthritis.