Exagen Inc. develops and sells testing products under the AVISE brand to diagnose, monitor, and prognose autoimmune and autoimmune-related diseases, including SLE and RA. Its lead product, AVISE CTD, enables differential diagnosis for patients with symptoms of various CTDs. The company also offers AVISE Lupus, AVISE APS, AVISE SLE Prognostic, AVISE Vasculitis AAV, AVISE Anti-CarP, AVISE PC4d, AVISE SLE Monitor, AVISE MTX, and AVISE HCQ. It has a research collaboration and license agreement with Allegheny Health Network Research Institute. The company was formerly known as Exagen Diagnostics, Inc. and is headquartered in Vista, California.