Provided are previously uncharacterised enhancer elements from the
preprotachykinin-A (PPTA) which shows transcriptional enhancement
activity in Substance P (SP) expressing cells. These are termed ECR1 and
ECR2. The invention provides nucleic acids comprising these sequences and
variants or fragments thereof, plus methods and materials based thereon,
such as transformed host cells, transgenic animals, and screening and
expression systems.