The predominant modes of action are thought to involve inhibition of tumor angiogenesis by decreasing the ratio of circulating proangiogenic factors (e.g., VEGF) and antiangiogenic factors (e.g., thrombospondin-1, TSP-1), which are secreted in the tumor microenvironment in tumor-bearing mice and patients with cancer3,7,10–14. This evidence concerns the gene THBS1 and neoplasm.