 This study evaluated the response in lung function to different treatment regimens for common variable immunodeficiency, CVID, patients with granulometous lymphocytic interstitial lung disease, GLILD. The study found that corticosteroid treatment improved gas exchange in CVID patients with GLILD, but patients often relapse. Mycophenolate mofdil, MMF, was associated with long-term effectiveness in GLILD and allowed for successful weaning of corticosteroids. Delaying initiation, or continuation of treatment, could lead to disease progression. This article was authored by Heber M. Bintalib, David M. Lowe, Gaya Mancuso, and others.