Supporting the later option are the observations that although almost all proteins carry sialic acids, the recognition of influenza by Ncr1 and NKp46 seems to have a certain unique specificity, as other glycosylated cell receptors such as KIR2DL1, KIR2DL2, NKp30, CD16, NKG2D and LIR1([6], [9] and data not shown) do not demonstrate increased binding to the infected cells. Here, KLRK1 is linked to influenza.