Mills AM, Huckins DS, Kwok H, Baumann BM, Ruddy RM, Rothman RE, Schrock JW, Lovecchio F, Krief WI, Hexdall A, Caspari R, Cohen B, Lewis RJ. Diagnostic characteristics of S100A8/A9 in a multicenter study of patients with acute right lower quadrant abdominal pain. Acad Emerg Med. 2012 Jan; 19(1):48-55.