Figure 3

Circle diagrams with the frequency of the study results and outcomes (below) of TLR4 polymorphism from the PubMed search. This search revealed that more than half of the studies do not find any association between susceptibility to infection and TLR4 polymorphisms (n = 157). In the top diagrams, the frequencies of the methodologies used are presented in the studies that showed a positive effect or no association of the investigated TLR4 polymorphisms. This figure shows that the majority of studies are based on genetic association studies, and a minority measured cytokine production following LPS stimulation of either whole blood or PBMCs. Overall, the contrast between study outcomes measuring the functional effects of TLR4 polymorphisms and of those looking at the role these have in susceptibility is revealed.