NSG-engrafting AML graft in NOD/SCID IL2Rγc^null mice is monoclonal. (A) Engrafted human cells and (B) de novo isolated NSG-AML samples were analyzed for TCRG gene rearrangements by heteroduplex formation. NOD/SCID IL2Rγc^null mice were transplanted with NSG-AML#22 and #23 and TCRG gene rearrangements were detected in engrafted mice by (C) heteroduplex formation and (D) PCR fragment size analysis.