Humaid O. Al-Shamsi1, Bryan K. Kee1, Michael T. Tetzlaff2, Robert A. Wolff1 Department of Gastrointestinal Medical Oncology, Department of Pathology, Division of Pathology/Lab Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas, TX 77030, USA Correspondence to: Humaid O. Al-Shamsi. Assistant Professor, Department of Gastrointestinal Medical Oncology, The University of Texas MD Anderson