To better understand the role for Tregs in lung fibrosis while also circumventing confounding technical issues, we leveraged previously developed inducible mouse models expressing high effect size variants in the surfactant protein C (SFTPC) gene found in patients with familial pulmonary fibrosis (FPF), sporadic IPF, and childhood interstitial lung disease (chILD), the most common of which is a missense variant in the linker domain of the surfactant protein C (SP-C) pro-protein (SftpcI73T)[23-25]. Here, SFTPC is linked to idiopathic pulmonary fibrosis.