The research of John S. Yu, MD, focuses on immune and stem cell therapy for brain tumors, cancer stem cells and their microenvironment in brain tumors. Dr. Yu also researches cancer stem cell-specific cytotoxic T lymphocytes, cancer stem cell signaling, mechanism of cancer invasion, cancer stem cell-specific cytotoxic T lymphocytes, targeted immunochemotherapy using nanotechnology, and development of imaging and diagnostic agents using nanoparticles.