As for the IL-4-590C/T, the frequency of the TT genotype was significantly higher among RA patients (7.05%) compared to controls (2.01%), and the frequency of the CT genotype was also higher among RA patients (29.00% versus 25.94%), but the frequency of the CC genotype was significantly lower among RA patients (63.96%) than controls (72.06%). This evidence concerns the gene IL4 and rheumatoid arthritis.