FN1 and infection: Ligands of the αMβ2 integrins include bacterial LPS which promotes recognition and engulfment of Gram negative bacteria such as E. coli, whilst α5β1 integrins bind the RGDS motifs of fibronectin and vitronectin [38–40] to enable macrophages to either eliminate apoptotic cells or migrate to sites of infection to increase their bactericidal activity [38,41].