First, we determined whether troglitazone affects the expression of VEGF-A and its receptors, fms-like tyrosine kinase (FLT-1/VEGFR1), kinase insert domain receptor 1 (KDR/VEGFR2), and neuropilin-1 (NRP-1) in the human lung cancer cell lines, RERF-LC-AI, SK-MES-1, PC-14, and A549 (Table 1). Here, NRP1 is linked to lung carcinoma.