LV-ADA2 restores ADA2 expression and enzymatic activity in patients’ CD34-derived cells. ADA2 expression was evaluated in CD34-derived cells (A) and supernatants (B), from 2 HDs and 2 patients, that were transduced with LV-ADA2 or LV-GFP at an MOI of 10 and 50. β-actin expression was included as a loading control. (C) ADA2 enzymatic activity was quantified in cell-free supernatants from ADA2- and GFP-transduced CD34-derived cells from 1 HD (HD1) and from 1 patient (patient 2 [PT2]).