N-myc, a transcription factor belonging to the myc basic Helix-Loop-Helix DNA binding domain family, was the only predicted miR-449a target in the MGI database to be associated to both abnormal branching morphogenesis and pulmonary hypoplasia in mouse models, and also expressed in lung epithelial cells like miR-449a. The gene discussed is MYCN; the disease is Pulmonary hypoplasia.