TEK and colorectal cancer: As we have now demonstrated the value of circulating Tie2 in ovarian11,12 and colorectal cancers, when treating patients with bevacizumab-cytotoxic chemotherapy combinations and others have described similar findings in colorectal cancer3, glioma2 and gall bladder6 cancer in trials of the VEGF RTKi, cediranib, it is credible that Tie2 is a generic circulating tumor vascular response biomarker for VEGF inhibitors.