CD45RA and γc expression in treated dogs are reconstituted compared with normal controls. (A) Flow cytometric evaluation of CD45RA expression in CD3⁺ T lymphocytes in a normal dog (top 2 panels) and in both in vivo gene therapy–treated dogs 1547 and 1655 at 4 months (left) and at 16 months (right) of age. Naive T lymphocytes are denoted by presence of CD45RA⁺ (top right quadrants). (B) Overlay of γc expression in peripheral blood lymphocytes from dog 1547 with γc expression in an age-matched normal dog.