There is a wealth of resources on the general topic of hematopoietic 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.