This family includes a number of bacterial surface antigens expressed on the surface of pathogens.

1: Derivation of the complete msp4 gene sequence of Anaplasma marginale without cloning. Oberle SM, Barbet AF; Gene 1993;136:291-294. PMID:8294020

2: Cloning and characterization of a gene encoding the major surface protein of the bacterial endosymbiont Wolbachia pipientis. Braig HR, Zhou W, Dobson SL, O'Neill SL; J Bacteriol 1998;180:2373-2378. PMID:9573188