Selected conditioning regimens of different dose intensities. AraC, cytosine arabinoside; ATG, antithymocyte globulin (or thymoglobulin); ¹³¹I, anti-CD45 antibody conjugated to ¹³¹I. BU, busulfan; CY, cyclophosphamide; Flu, fludarabine (various dosing schedules). *High-dose TBI (800-1320 cGy). ^†Low-dose TBI (200-400 cGy). Reproduced from Deeg and Sandmaier.¹⁰⁶