Different Activity of the Biological Axis VEGF-Flt-1 (fms-Like Tyrosine Kinase 1) and CXC Chemokines between Pulmonary Sarcoidosis and Idiopathic Pulmonary Fibrosis: A Bronchoalveolar Lavage Study. Here, FLT1 is linked to idiopathic pulmonary fibrosis.