TLR9 and systemic inflammatory response syndrome: Duramad et al. found that injection of immunoregulatory DNA sequences, which act systemically to block TLR-9 stimulation, into mice could prevent the systemic inflammatory response syndrome (SIRS) [36], suggesting that the occurrence of SIRS in allo-HSCT patients carrying the TLR9 gene variant is significantly lower than that in patients with the wild-type TLR9 gene.