Improved respiratory function in LV-SF-GAA–treated mice. Whole-body plethysmography was performed to determine (A) peak inspiratory flow, (B) tidal volume, and (C) frequency of breathing in 11-month-old mice (WT, n = 5; LV-SF-GFP, n = 3; LV-SF-GAA, n = 6, at 9 months after transplantation). All mice were exposed to increasing doses of nebulized metacholine to test muscular weakness or exhaustion of Gaa^−/− mice. The peak inspiratory flow, tidal volume, and frequency of breathing are reduced in animals that received a transplant of LV-SF-GFP compared with WT mice. LV-SF-GAA transplantation improves both parameters relative to LV-SF-GFP (*P < .05, **P < .01). BL indicates baseline; SA, saline.