Increasing evidence indicates that global chromatin remodeling events underlie normal and leukemic hemopoiesis but the mechanisms involved have been unclear. Dr Lessard is a young principal investigator at Institut de Recherche en Immunologie et en Cancerologie (IRIC). Her Tier II Chair in Molecular Genetics of Stem Cell Hematopoiesis was created in 2007, based on a program aimed at deciphering the role of SWI/SNF-like BAF chromatin remodeling complexes in the developing hemopoietic system and in leukemia. Her most recent work indicates that subunit exchange within a novel family of hemopoietic BAF complexes orchestrates normal and leukemic hemopoiesis. Strikingly, she finds that some subunits are essential for HSC function, while others are required later in the hemopoietic hierarchy for the development of specific lineages. Perhaps most provocatively, her studies indicate that BAF subunits are combinatorially assembled into functionally specialized complexes in the developing hemopoietic system and in leukemia and that adroit targeting of subunits specifically expressed in leukemic stem cells (LSCs) may have potent and specific therapeutic effects.