1. A method of treating cardiovascular disease in a mammal comprising the step of transfecting cells of said mammal with a polynucleotide, which encodes VEGF145. 2. The method according to claim 1, wherein said polynucleotide is cloned into a vector. 3. The method according to claim 2, wherein said vector comprises adenovirus particles. 4. The method of claim 3, wherein said adenovirus vector particles are delivered to said mammal by injection. 5. The method of claim 4, wherein the number of said adenovirus particles is between about 10&lt;10&gt; to about 10&lt;14&gt;. 6. The method of claim 5, wherein the number of said adenovirus particles is between about 10&lt;11&gt; to about 10&lt;13&gt;. 7. The method of claim 1, wherein said transfected cells are heart cells. 8. The method of claim 4, wherein said transfected cells are coronary artery cells and wherein said injection is intracoronary injection. 9. The method of claim 8, wherein said adenovirus particles are injected at about 1 cm into the lumens of the left and right coronary arteries. 10. The method according to claim 1, wherein said cells are transfected in vivo. 11. The method according to claim 1, wherein said cells are transfected ex vivo. 12. The method according to claim 8, wherein said polynucleotide is introduced into said coronary artery cells by a catheter inserted into said artery. 13. The method according to claim 12 wherein said catheter comprises an inflatable balloon having an outer surface adapted to engage the inner wall of said artery, and wherein said polynucleotide is disposed upon said balloon outer surface. 14. The method according to claim 1, wherein said polynucleotide comprises the base sequence as defined in the Sequence Listing by SEQ ID No. 1. 15. The method of claim 1, wherein said mammal is human. 16. An expression vector comprising a polynucleotide sequence encoding aVEGF145 species, said species being selected from the group consisting of: (a) VEGF145, (b) a biologically active fragment of VEGF145; and (c) a biologically active derivative of VEGF145, wherein one or more amino acid residues have been inserted, substituted or deleted in or from the amino acid sequence of the VEGF145, or its fragment. 17. The expression vector according to claim 16, wherein said species is VEGF145. 18. The expression vector according to claim 16, wherein said polynucleotide comprises the base sequence as defined in the Sequence Listing by SEQ ID No. 1. 19. The expression vector according to claim 16, wherein said polynucleotide is flanked by adenovirus sequences. 20. The expression vector according to claim 19, wherein said polynucleotide sequence is operably linked at its 5&#39;-end to a promoter sequence that is active in vascular endothelial cells. 21. The expression vector according to claim 19, wherein said expression vector is an adenovirus vector. 22. The expression vector according to claim 21, wherein said vector further comprises a partial adenoviral sequence from which the E1A/E1B genes have been deleted. 23. A kit for intracoronary injection of a recombinant vector expressing VEGF145 comprising: (a) a vector suitable, according to claim16, for expression of said polynucleotide in vivo, (b) a suitable container for said vector, and (c) instructions for injecting said vector into a patient. 24. The kit according to claim 23, wherein said polynucleotide is cloned into an adenovirus expression vector. 25. A method of treating vascular disease in a mammal comprising the step of administering to said mammal VEGF145 in a therapeutically effective amount to stimulate vascular cell proliferation. 26. A method for enhancing endothelialization of diseased vessels comprising the step of administering to a mammal a therapeutically effective amount of VEGF145. 27. The method of claim 26, wherein said endothelialization is reendothelialization after angioplasty. 28. The method of claim 27, wherein said reendothelialization reduces or prevents restenosis. 29. The method of claim 27, wherein said patient is treated with a stent. 30. The method of claim 27, wherein said patient is treated without a stent. 31. The method of claim 26, wherein said mammal is human. 32. The method of claim 25, wherein said administration comprises gene therapy. 33. The method according to claim 32, wherein an inflatable balloon catheter coated with a polynucleotide encoding VEGF145 is employed to administer said gene therapy. 34. A method of enhancing drug permeation by tumors comprising administering to a patient a nucleic acid molecule coding forVEGF145. 35. The method of claim 34, wherein said VEGF145 is delivered directly into a tumor cell. 36. A therapeutic composition comprising a pharmaceutically acceptable carrier and VEGF145 in a therapeutically effective amount to stimulate vascular cell proliferation. 37. A filtered injectable adenovirus vector preparation, comprising: a recombinant adenoviral vector, said vector containing no wild-type virus and comprising: a partial adenoviral sequence from which the E1A/E1B genes have been deleted, and a transgene coding for a VEGF145, driven by a promoter flanked by the partial adenoviral sequence; and a pharmaceutically acceptable carrier.