Dr Cindy Ma is head of the Human Immune Disorders Group in the Immunology Division at the Garvan Institute of Medical Research. She is a NSW Health Early-Mid Career Fellow and a conjoint senior lecturer at St Vincent’s Clinical School, UNSW, Sydney. She has studied and worked for >15 years in the fields of human lymphocyte biology and primary immunodeficiency. Her research interests stem from her PhD, which investigated the lymphocyte defects in the rare primary immunodeficiency, X-linked lymphoproliferative disease. She was awarded a PhD in 2006 from the University of Sydney. That same year she moved to the Garvan Institute where her group has continued to investigate primary immunodeficiencies to understand how monogenic mutations in critical genes result in lymphocyte dysfunction, and subsequent disease in affected individuals. Furthermore, by investigating these rare individuals, her research has uncovered distinct and fundamental aspects of human CD4+ T cell biology.