Exagen Inc. is a provider of autoimmune diagnostics focused on transforming care for patients with chronic and debilitating autoimmune conditions. The Company is focused on the design, development and commercialization of a portfolio of testing products under its AVISE brand, which allow for the differential diagnosis, prognosis and monitoring of complex rheumatic, autoimmune and autoimmune-related diseases, including systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). Its testing products are supported by two proprietary technologies: its AVISE Lupus platform, which incorporates Cell-Bound Complement Activation Products (CB-CAPs) for diagnosing SLE, and a set of three biomarkers, the t-cell-based CB-CAP TC4d, along with two t-cell antibodies, TIgG, and TIgM (the T-Cell Biomarkers), all of which are incorporated into its AVISE CTD product. The Company’s flagship product, AVISE CTD, enables clinicians to more effectively diagnose complex autoimmune conditions.