Support is requested for organizing the third conference on hemopoietic stem cell gene therapy to be held November 1-4, 2001, in Rockville, Maryland. It will represent a gathering of molecular biologists working on gene transfer and on development of gene therapy technology, and cell biologists and clinical investigators addressing the biological and clinical issues of gene transfer into hemopoietic stem cells. Session I - Hematopoietic Stem Cell Phenotype and Behavior. Session II. Stem Cell Physiology. Session III. Vectors for Gene Transfer into Hematopoietic Stem Cells. Session IV. Preclinical Evaluation of Stem Cell Gene Therapy Vectors. Session V: Large Animal Gene Transfer. Session VI. Summary of Clinical Trials Involving Stem Cell Gene Transfer. Session VII: Stem Cell Plasticity Session VIII: Stem Cell Plasticity. One hundred-fifty to 200 participants are expected. The conference will be advertised. A special effort will be made to encourage attendance by postdoctoral fellows and graduate students.