To evaluate the in vivo uptake of eBT-IDS1 and eBT-IDS2 by brain tissue, AAV8 vectors encoding either the eBT-IDS1 or eBT-IDS2 transgene under the control of the TBG promoter were packaged and administered to 4- to 6-week-old MPS II mice via intravenous injection (1 ​× ​1011 GC/mouse). Here, IDSP1 is linked to mucopolysaccharidosis type 2.