IL4 and periodontitis: When comparing genotypes (IL-4 -590CC versus CT + TT and IL-4 VNTR 11 versus 12 + 22) between patients with the slight/moderate (N = 13) and severe (N = 32) form of periodontitis, we found no statistically significant differences between both groups (P = 0.50 for IL-4 -590C/T and P = 0.61 for IL-4 VNTR polymorphisms).