ABCD1 and X-linked adrenoleukodystrophy: Additionally, in an X-ALD mouse model, HITI-AAV vectors enabled precise integration of human ABCD1 near the 5′-UTR of Abcd1. Treated mice showed significant ABCD1 mRNA expression and reduced concentrations of the diagnostic markers C24:0-LysoPC (Lysophosphatidylcholine) and C26:0-LysoPC.