IL6 and rheumatoid arthritis: As for the IL-6-174G/C, the frequencies of the GG, GC, and CC genotypes were 81.52%, 16.49%, and 2.00% in RA patients, significantly different from those observed in controls, which were determined to be 98.50%, 1.25%, and 0.25%, respectively (χ2 = 127.0661,  P = 2.5582 × 10−28 < 0.001).