PTP4A3 and periodontitis: Among them, HLA-C (IVW, nine SNPs, p=0.03) was identified as a risk factor for periodontitis, while STAP1 (IVW, four SNPs, p=0.01) and PTP4A3 (IVW, 10 SNPs, p=0.04) were recognized as protective factors (Figure 4D).