May have roles in host-pathogen interaction, including establishment and maintenance of biotrophy, prevention of host recognition of the fungus and a barrier to host defense molecules. Forms a multimeric structure. Cell wall and surrounding interfacial matrix. Expressed in penetration hyphae, infection vesicles and primary hyphae (intracellular hyphae). Expressed during the biotrophic phase of host-pathogen interaction. N-glycosylated and may be O-glycosylated.