Exagen Diagnostics, Inc. is a United States-based commercial-stage diagnostics company that develops and sells diagnostic tests. The Company provides physicians with clinical tools that address the significant unmet need for diagnosis, prognosis and monitoring of autoimmune connective tissue disease (CTD). Its AVISE product line encompasses six game-changing products: AVISE CTD, AVISE SLE Prognostic, AVISE TDM, AVISE Infliximab, AVISE Adalimumab, AVISE MTX and AVISE HCQ. AVISE CTD is a diagnostic tool to help distinguish overlapping symptoms and aid in the differential diagnosis of lupus, fibromyalgia, scleroderma and autoimmune thyroid disease. AVISE SLE Prognostic is a risk assessment testing for organ involvement. AVISE Infliximab, AVISE Adalimumab, AVISE MTX and AVISE HCQ are its therapeutic drug monitoring tools designed to help physicians assess and individualize patient therapy by offering serologic data to inform dosing decisions and determine drug efficacy.