[1] Johns Hopkins Univ, Sch Med, Dept Mol & Genet, Baltimore, MD USA
[2] Johns Hopkins Univ, Sch Med, Dept Med, Baltimore, MD 21205 USA
[3] Mayo Clin, Sch Med, Devis Gastroenterol & Hepatol, Rochester, MN USA
[4] Johns Hopkins Univ, Sch Med, Howard Hughes Med Inst, Baltimore, MD 21205 USA
[5] Texas A&M Hlth Sci Ctr, Dept Med, Temple, TX USA
[6] Texas A&M Hlth Sci Ctr, Scott&White Digest Dis Res Ctr, Temple, TX USA
[7] Cent Texas Vet Hlth Care Syst, Res Serv, Temple, TX USA