We have used FR-sema3C rather than wild type sema3C even though both function as effective inhibitors of angiogenesis [23,30], because previous observations we have made suggest that p65-Sema3C, the main FPPC cleavage product derived from sema3C, functions, unlike full length sema3C, as a survival/mitogenic factor for some tumor cell types [30]. This evidence concerns the gene SEMA3C and neoplasm.