Dr. Ellis is interested in all aspects of cancer. His work includes articles and publications in medical journals, as well as serving as the Chief, in the Division of Hematology and Oncology at Southwest Texas Methodist Hospital. He serves as a Clinical Professor of Medicine, Department of Medicine at The University of Texas Health Science Center in San Antonio. Dr. Ellis also serves as the Medical Director of the in-patient Hospice Unit and of Palliative Care for Methodist Healthcare.