KDR and idiopathic pulmonary fibrosis: In the clinical setting, Richeldi et al. treated patients with idiopathic pulmonary fibrosis (IPF) for 1 year with nintedanib (formerly known as BIBF 1120), an intracellular inhibitor that can block multiple tyrosine kinase receptors such as PDGFRβ and VEGFR-2 [167].