EXAGEN INC.

We are a medical technology company primarily focused on the design, development and commercialization of a next-generation portfolio of innovative testing products under our AVISE brand, which allow for the differential diagnosis, prognosis and monitoring of complex rheumatic, autoimmune and autoimmune-related disease including, among others, systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). We believe our strong focus and extensive background in the field of rheumatology, combined with our commitment to exceptional customer service and support, position us well to respond to the needs of rheumatologists, primary care physicians, other specialists, and the patients they serve. Our tests are used in a variety of clinical settings to provide clarity in autoimmune disease decision-making with the goal of improving patients' clinical outcomes. We commercially launched our flagship testing product, AVISE CTD, in 2012. AVISE CTD enables differential diagnosis for patients presenting with symptoms indicative of a wide variety of connective tissue diseases (CTDs) and other related diseases with overlapping symptoms. Traditional screening methods often lack accuracy, resulting in repeat testing and delayed diagnosis. With significant increases in autoimmune incidence in recent years, AVISE CTD provides unique biomarkers that empower clinicians to confidently and quickly diagnose various CTDs.