NOD2 and Arthritis: More recently, specific NOD2 variants have been associated with Yao syndrome (YAOS), previously known as NOD2-associated autoinflammatory disease, a polygenic AID with characteristic features of episodic fever, dermatitis, arthralgia/arthritis, pleuritis, gastrointestinal symptoms, distal extremity swelling, and sicca-like symptoms (13–17).