Based on recent studies showing that infiltrating mononuclear cells and especially CD8+ TLs could be implicated in the pathogenesis of IPF and the observation that in IPF the TL subpopulations recovered by BAL relate to those in lung tissue [9,10], we further evaluated the relationships between BAL cells and physiologic and clinical parameters of disease severity in IPF patients. Here, CD8A is linked to idiopathic pulmonary fibrosis.