XK and influenza: Apart from individual immunity discrepancy, it is projected that the high virulence and pathogenesis of influenza strains also is caused by the specific sequence of viral proteins and mutations occurred in critical regions [8,9], including the external surface glycoproteins, hemagglutinin (HA) and neuraminidase (NA) in relation to their interaction with sialic acids, the viral specific receptor on host cells [3,10-12].