,52 In the ALD trials there were some clones showing clonal dominance with over-representation of the insertion site near SMG6, CCND2, and HMGA2, but this has not led to development of leukemia and may be transient, as was reported for a SIN LV vector used for treating β-thalassemia.53 This evidence concerns the gene SMG6 and X-linked adrenoleukodystrophy.