There is a wealth of resources on the general topic of hematopoietic <!g>stem cells and their clinical uses. Because of the nature of primary and secondary diseases requiring hematopoietic stem cell transplant, the most comprehensive, up-to-date information can be found through one of the many National Cancer Institute-designated Comprehensive Cancer Centers. Particularly useful are http://oncolink.upenn.edu and http://www.fhcrc.org.