DMBT1 and infection: Mucus is supposed to prevent infection by restricting the access and by the antiviral action of various proteins, such as β-defensin, lactoferrin, palate lung and nasal epithelium clone (PLUC), cathelicidins (LL-37), SP-A and SP-D, deleted in malignant brain tumor 1 (DMBT1) and galectins [13].