Dr. Snoeck was trained as a clinical hematologist, with a focus on bone marrow transplantation; from that clinical interest developed a research program in hematopoietic stem cell biology, more specifically mechanisms regulating stem cell renewal and underlying quantitative genetic variation in the behavior of hematopoietic stem cells among inbred mouse strains. After identification of Prdm16 allelic variation as one of the underlying mechanisms, his lab now focuses on the mechanism of action of Prdm16 in the renewal of hematopoietic stem cells. Expansion of this program into directed differentiation of ES and iPS cells in thymic epithelial cells arose from the desire to attempt to alleviate post–bone marrow transplantation immune deficiency, caused by, for example, defective T cell reconstitution. These studies led to a strategy to generate anterior foregut endoderm from human pluripotent stem cells, from which lung and airway are derived. Further development of this program led the lab to the forefront of the field of directed differentiation of human pluripotent stem cells into lung and airway epithelial cells.