2. Study hypothesis In our recent in vitro study, addition of simvastatin to bevacizumab reduced proliferation, migration, invasion and tumor formation of endothelial cell. Moreover, colorectal cancer cell media which was treated with simvastatin combined with bevacizumab inhibited endothelial cell invasion and it was associated with decreased mediator of angiogenesis, such as angiopoietin 2, BiP and HSP 90α.. Treatment with bevacizumab and simvastatin more reduced the growth of xenograft tumors compared with bevacizumab alone.