Discloses a plasmid comprising a sequence encoding all or part of a disintegrin domain of a matargidin of disclosed SEQ ID NO: 1 that is under the control of the cytomegalovirus promoter. The disclosed sequence is a variant of the cDNA sequence of the wild-type disintegrin domain in which one or more nucleotides are substituted, added or deleted from SEQ ID NO: 1 and which has at least 80% sequence identity to SEQ ID NO: 1. A plasmid carrying the disclosed sequence has the capacity to inhibit endothelial cell proliferation and/or inhibition of angiogenesis in vitro and/or in vivo, when the plasmid is inserted into a host cell by transfection. Further provides methods for recovery of the plasmid from host cells. Further provides for use of the plasmid for the manufacture of a medicament for the treatment of tumours. Further discloses a method to assess plasmid mediated effects on tumour cell proliferation in vitro.
