CD44 and infection: Hyaluronan has shown capacity to exert antiviral activity by different mechanisms, such as acting as decoy receptor, limiting the infection of unstimulated CD4 + T helper cells in a CD44-dependent manner, binding to envelope ligand sites, or disrupting viral docking, internalization and uncoating in host cells; it has also been demonstrated to enhance the host immune response by stimulating the release of antiviral mediators (15, 90).