1. Institute for Clinical and Translational Research, Baylor College of Medicine, Houston, TX, U.S.A.
2. Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, U.S.A.
3. Section of Epidemiology and Population Sciences, Department of Medicine, Baylor College of Medicine, Houston, TX, U.S.A.
4. Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX, U.S.A.