IL13 and periodontitis: The pooled analyses using these models indicated that the IL-13 -1112C/T polymorphism was significantly associated with susceptibility to periodontitis (CC vs TT: OR = 0.615, 95% CI = 0.395–0.957; CTvsTT: OR = 0.518, 95% CI = 0.323–0.830;and TT vs CT + CC: OR = 1.739, 95% CI = 1.130–2.676).