In detail, a series of SNPs affecting key molecules of innate immunity including surface molecules such as TLR2, TLR4, TLR5 and different variants of the mannose-binding lectin 2 or intracellular downstream molecules as the IL-1 receptor-associated kinase and the TIR-domain-containing adaptor protein have been attributed with an increased risk of infections (Ahmad-Nejad et al,. This evidence concerns the gene TLR4 and infection.