IRF5 and systemic lupus erythematosus: Haplotype analysis identified protective haplotype HT1 (A/G, OR = 0.54, 95% CI: 0.41-0.73, <i>p</i> < 0.001) and risk haplotype HT4 (G/T, OR = 2.51, 95% CI: 1.42-4.42, <i>p</i> = 0.001).<h4>Conclusions</h4>These findings indicate that <i>IRF5</i> gene variants substantially modulate susceptibility to SLE in the Han Chinese population.