TLR2 and cystic fibrosis: The factors that confer additional virulence to R morphotypes remain obscure, but it has been postulated that glycopeptidolipids mask immunostimulatory cell wall components, TLR-2 ligands such as phosphatidyl-myo-inositol mannosides, lipomannan and lipoarabinomannan, that enable S variants to colonize the respiratory tract of patients with cystic fibrosis or bronchiectasis (Qvist et al., 2013), prior to the switch to R morphotypes lacking glycopeptidolipids and expressing these TLR-2 ligands on the cell surface (Gilleron et al., 2008; Rhoades et al., 2009).