He has been actively involved in cancer biology, cancer immunology and immunotherapy. He has discovered a number of tumor antigens and cancer stem cell (CSC)-specificantigens, and established a novel category of cancer stem testis antigens through somato-germinomics. He has been conducting clinical trials of CSC-targeted vaccines. Additional research interests arecellular stress responseand stress pathobiology, which underlie a variety of human diseases, including cancer, immune disorders, and neurodegenerative diseases. He has published more than