In 2004, Munchhof et al. reported the synthesis of substituted 7-(indol-5-yl)aminothieno [3,2-b]pyridines and their potential as inhibitors of the vascular endothelial growth factor receptor 2 (VEGFR-2), which is a receptor of tyrosine kinase that triggers signalization pathways that cause endothelial cell proliferation and tumor vascularization (angiogenesis) [5]. This evidence concerns the gene KDR and neoplasm.