SMAD3 and rheumatoid arthritis: Regarding this, when association between SMAD3 rs17228212 polymorphism and cIMT values was adjusted for potential confounders in the ANCOVA model, results disclosed that the presence of the C allele in the subgroup of anti-CCP negative RA patients was associated with significantly lower cIMT values than those found in anti-CCP negative patients carrying the T allele (p-value=0.0094).