This study also demonstrated that hMSCs promoted CD4+CD25+CD127(low/−)/foxp3+Tregs expansion in T cell subsets from patients with idiopathic pulmonary fibrosis and inhibitedCD3+CD8+cytotoxic T cells and CD3+CD56+ NKT cells proliferation in an experimental cell model. Here, CD4 is linked to idiopathic pulmonary fibrosis.