To determine whether rs1800629 genotypes influenced TNF-a production, we investigated TNF-a levels in culture supernatants of PBMCs obtained from 24 healthy volunteers. We observed a significant association between TNF-a levels and rs1800629 genotypes under the LPS-stimulated condition. AA+AG genotypes were associated with higher levels of TNF-a compared with GG genotype after LPS stimulation (P = 0.007) ( Figure 1 ). However, no significant association was observed under the unstimulated condition.