Modularization of the TLR signalling network showing I–O paths. Tree, 𝒯M, returned by the MIDIA algorithm tailored to analyse the I–O paths of the network (see text). Modules containing external input processes are coloured red and those containing outputs blue. Edges on the path between any input and any output module are uniquely numbered (with the number of species in the edge also shown in parentheses)—the colours of edges match the ones used in figure 6. Species names are as in [28], table S1) where L and LIG both denote a receptor ligand, but with the following exceptions: NOD1I(e) is the external input process for the NOD1 receptor, and similarly for NOD2I(e); NADPH-OX-3P(v) corresponds to PHOX-GTP-3P(v) in ([28], table S1), and similarly for NADPH-OX-8P(v).