 SAN DIEGO, Jan. 21, 2021 GLOBE NEWSWIRE -- Exagen Inc. Nasdaq: XGN, an organization dedicated to transforming the care continuum for patients suffering from autoimmune diseases, announced today that all AVISE test offerings CTD, Lupus, SLE Prognostic, SLE Monitor, APS, Vasculitis AAV, MTX, and HCQ are now a contracted in-network service with Tufts Medical Center, an internationally-respected academic medical center. 