XGN

Exagen Inc.

A medical diagnostics company, Exagen makes blood tests that help rheumatologists tell apart autoimmune conditions like lupus and rheumatoid arthritis. Its flagship product, AVISE CTD, is processed in a single lab in Vista, California, with results typically ready in about five business days. Founded in 2002, the company grows its line of AVISE-branded tests, and the "CTD" in its flagship test's name stands for connective tissue disease—the family of illnesses it helps doctors sort out.