Department of Translational Molecular Pathology The Graduate School of Biomedical Sciences, The University of Texas Health Science Center at Houston, Houston, TX, USA.|Department of Translational Molecular Pathology Department of Epidemiology.|Department of Translational Molecular Pathology Department of Epidemiology.|Department of Epidemiology.|Department of Translational Molecular Pathology Department of Gastrointestinal Medical Oncology Department of Clinical Cancer Prevention, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.|The Graduate School of Biomedical Sciences, The University of Texas Health Science Center at Houston, Houston, TX, USA Department of Epidemiology.