XK and influenza: Influenza (or, more commonly, flu) is a highly contagious acute respiratory infection caused by single-stranded RNA segmented influenza viruses of the Orthomyxovirus family, which are classified into four genera known as influenza A, B, C, and D viruses [76], as well as into subtypes based on hemagglutinin (HA) and neuraminidase (NA) surface proteins [112].