- Characterization of a polymorphic Theileria annulata surface protein (TaSP) closely related to PIM of Theileria parva: implications for use in diagnostic tests and subunit vaccines. Schnittger, L., Katzer, F., Biermann, R., Shayan, P., Boguslawski, K., McKellar, S., Beyer, D., Shiels, B.R., Ahmed, J.S. Mol. Biochem. Parasitol. (2002)