Expression cassette coding for vascular endothelial growth factor

A vector to express one or more VEGF isoforms, comprising:

• an expression cassette comprising a promoter operably linked to a nucleic acid sequence comprising VEGF exons 1-5, 6A, 7, and 8 which is linked to at least one polyA sequence, wherein the polyA sequence has reduced readthrough relative to an individual SV40 polyA sequence, wherein the splice acceptor (SA) of exon 8 is modified to enhance splicing at the splice acceptor of exon 8, wherein a sequence 3′ to the expression cassette is modified to mutate a downstream SA site, wherein if the vector is an adenovirus vector the polyA sequence has reduced readthrough adenovirus early gene expression and higher transgene expression relative to an individual SV40 polyA sequence, wherein the expression cassette is in reverse orientation relative to at least one other functional element that is 5′ or 3′ to the expression cassette, or a combination thereof.