Dr. Reiner has made significant contributions to our understanding of Immunology and Infectious Diseases, most notably demonstrating that our lymphocytes act like stem cells to repopulate our immune defense while simultaneously delivering diverse functions that eliminate viruses, germs and cancer. His group's discovery in 2007 that lymphocytes use asymmetric cell division in order to execute function while regenerating was chosen by Science magazine as one of the top ten scientific breakthroughs of the year. Dr. Reiner is an elected member of the American Society of Clinical Investigation and the Association of American Physicians.