MSN and autoimmune disease: Moesin is a membrane organizing protein that plays a role in immunologic synapse formation, lymphoid cell regulation, and T regulatory cell (Treg) differentiation.68,69 In this last regard, there is evidence that a shift in the T helper cell 17 (Th17)/Treg balance toward the proinflammatory Th17 axis contributes to the development of Sjögren syndrome and other autoimmune disorders.70, , –73 The reasons for this shift are not completely known, but may be due, at least in part, to moesin activity and other microenvironmental stimuli.52