GSTA4 and periodontitis: Similarly, GSTA4 (5 SNPs, OR = –0.205, 95% CI: –0.391 to –0.020, p=0.031), NYNRIN (5 SNPs, OR = –0.174, 95% CI: –0.298 to –0.050, p=0.006), and IGKV2D-30 (3 SNPs, OR = –0.405, 95% CI: –0.809 to –0.002, p=0.049) were all inversely associated with periodontitis, implying potential protective roles.