The equilibration of brain-resident Treg cells in control and treated mice, 4+ weeks after initial PHP.GFAP-IL-2 treatment, across both stroke and EAE, suggests either a maximal duration of efficacy following a single AAV dose, or a confounding effect of pathology-derived Treg cells obscuring the treatment-derived Treg cell increase. The gene discussed is IL2; the disease is stroke disorder.