B4GALNT2 and influenza: The selective pressure affecting B4GALNT2 expression may derive from host pathogen interactions as the absence of B4GALNT2 expression and altered glycosylation of the intestinal epithelia is associated with significant shifts in the composition of the microbiota,73 which can effect host sensitivity and pathologic responses to infection.74 Other variations in B4GALNT2 expression are reported in ovarian follicles of FecLL carrier sheep, where it is linked to increased fecundity75 and in respiratory tract expression in the ferret where high SDa expression reduces influenza infectivity.76