In this issue of Blood, MacMillan et al give the results of sequential modifications of the conditioning regimen to improve the outcome of unrelated bone marrow transplantation in Fanconi anemia (FA). Over a period of 10 years, they show that transplant toxicity has decreased and engraftment has improved, resulting in a 5-year overall survival probability of 94%. The major change was the use of fludarabine in the conditioning, with decreased doses of irradiation and cyclophosphamide. They attribute their success to progressive modifications of the conditioning regimen; nevertheless, the improvement may also have been due to better patient selection, use of high-resolution HLA typing for donor selection, and improved supportive care treatment.