FLT4 and ductal breast carcinoma in situ: We studied protein expression of basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF)-A, endothelin (ET)-1, and VEGF-C, and their receptors bFGF-R1, Flt-1, KDR, ETAR, ETBR, and Flt-4 immunohistochemically in 200 DCIS (pure DCIS: n=96; DCIS adjacent to an invasive component: n=104) using self-constructed tissue microarrays.