Moreover, experimental studies in murine and rat models have confirmed that excessive TLR9 activation may impair pregnancy, as stimulation with TLR9 agonists, such as CpG oligodeoxynucleotides (ODNs), cffDNA, or mtDNA was shown to induce IUGR [21], PE [17,24], fetal resorption [16,22,25,26,27], and preterm birth [25,27]. The gene discussed is TLR9; the disease is fetal growth restriction.