FLT4 and breast carcinoma: Breast cancer cell lines with high VEGF expression have been reported to also express high levels of interleukin-8 (IL-8), suggesting that they play very crucial roles in the promotion of angiogenesis in breast cancer angiogenesis, 100-103 A high level of VEGF receptor-3 has been detected in invasive breast cancer and also found to be upregulated in the endothelium of angiogenic blood vessels.