In fact, in vitro studies have determined that sVEGFR-2 can be found in the conditioned media of proliferating mouse and human endothelial cells, but not of colon cancer cells (e.g., HT-29; Ebos et al, 2008), thus suggesting that it may be secreted, similar to soluble VEGFR-1, or proteolytically cleaved from the cells of tumour microenvironment (Ebos et al, 2004). This evidence concerns the gene FLT1 and malignant colon neoplasm.