The repair of the epithelial barrier is believed to involve the transdifferentiation of type II cells into type I epithelial cells.8 The inability of type II AECs to transdifferentiate into type I AECs have also been observed in human lung fibrosis.40 Our study showed that RvD1 promoted gene expression of AQP5 (type I marker) in ATII cells via activation of ALX supporting a potential role for RvD1 in promoting fluid transport. The gene discussed is AQP5; the disease is pulmonary fibrosis.