- Mutations in a conserved residue in the influenza virus neuraminidase active site decreases sensitivity to Neu5Ac2en-derived inhibitors. McKimm-Breschkin, J.L., Sahasrabudhe, A., Blick, T.J., McDonald, M., Colman, P.M., Hart, G.J., Bethell, R.C., Varghese, J.N. J. Virol. (1998)