SYN1 and neurodegenerative disease: Taking into account that (i) SYN1 is expressed from only one allele, (ii) both SYN1 transcripts are driven by the same promoter, and (iii) proven enhancer elements (i.e. the WPRE) can be an integral part of the transgene expression cassette, the porcine SYN1 promoter presents as a good choice for establishing models of neurodegenerative diseases.