TGFB1 and acute respiratory distress syndrome: Quesnel and co-authors reported in their first study that a limited population of fibrocytes was detectable during the initial phase of BAL culturing, alveolar fibroblasts can be cultured from BAL in 25% of ALI/ARDS patients, the migration of alveolar fibroblasts of the study group was three-fold to that of the control group, and collagen I production was elevated in alveolar fibroblasts and correlated with TGF-β production [7].