[1] Mayo Clin, Dept Lab Med & Pathol, Rochester, MN USA
[2] Univ Penn, Dept Pathol & Lab Med, Philadelphia, PA USA
[3] Univ Iowa Hlth Care, Dept Surg, Iowa City, IA USA
[4] Univ Iowa Hlth Care, Dept Internal Med, Iowa City, IA USA
[5] Univ Iowa Hlth Care, Dept Pathol, Iowa City, IA USA
[6] Univ Iowa Hlth Care, Neuroendocrine Canc Program, Iowa City, IA USA
[7] Brigham & Womens Hosp, Dept Pathol, 75 Francis St, Boston, MA 02115 USA