The Deans laboratory has worked principally on B cell antigen receptor signaling mechanisms and the structure and function of CD20 (MS4A1), contributing to the understanding of the topology and extracellular epitopes of CD20, its association with the B cell antigen receptor, role in receptor-activated calcium influx, and its requirement for optimal humoral immunity. More recently, the laboratory has evaluated expression of other members of the MS4A family, focusing mainly on expression of MS4A4A and MS4A8B using monoclonal antibodies made in-house against extracellular epitopes.