Immune white cells, such as cytotoxic T lymphocytes (CTL) and natural killer (NK) cells, protect us from infectious diseases and cancer by killing infected or unwanted cells. Defects in the function or regulation of these cells can lead to immunodeficiency or autoimmunity. Two childhood diseases resulting from autoimmune malfunction include the common disease, type 1 diabetes (T1D), and X-linked lymphoproliferative (XLP) disease—a rare immunodeficiency. Dr. Rusung Tan studies the role of these cells in T1D and XLP. He is working to determine how defects in the molecular and cellular function of cytotoxic immune cells lead to disorders of childhood and will translate these findings into improved diagnostic tools, preventions and therapies for disease. His personal goal is to use the successes achieved in this work as models to drive the overall development of childhood immunity research in British Columbia.