- Lactoferrin Glu561Asp polymorphism is associated with susceptibility to herpes simplex keratitis. Keijser, S., Jager, M.J., Dogterom-Ballering, H.C., Schoonderwoerd, D.T., de Keizer, R.J., Krose, C.J., Houwing-Duistermaat, J.J., van der Plas, M.J., van Dissel, J.T., Nibbering, P.H. Exp. Eye Res. (2008)