IRAK1 and infection: In the onset of infection, evolutionarily conserved structural elements residing on the bacteria’s exterior, termed PAMPs, e.g., flagellin, peptidoglycan (PGN), and lipopolysaccharides (LPS), are recognized by host PRRs, e.g., TLRs, to trigger two major signaling pathways: the Myd88/IRAK1,4/TRAF6/TAK1/IKK/NF-ĸB pathway and the Myd88/IRAK1,4/TRAF6/ TAB2,3)/TAK1/MAPK (JNK/p38)/ pathway (Figure 1E).