Helen Heslop is a physician-scientist engaged in translational research focusing on adoptive immunotherapy with gene-modified effector cells, to improve hemopoietic stem cell transplantation and cancer therapy. A key step in this strategy has been the translation of laboratory findings to Phase I and II clinical trials, as exemplified by studies of Epstein Barr virus-induced lymphoproliferative disease (EBV-LPD), a fatal complication in about 15% of recipients of unrelated or mismatched family member bone marrow transplants in the early 1990s. In collaboration with Dr Cliona Rooney, she developed methods for early diagnosis of this disease and procedures for generating cytotoxic T lymphocytes (CTLs) from bone marrow donors.