Somatostatin is a multi-functional peptide hormone; originally thought to be a growth hormone inhibitor however functions have been found to be more diverse and can be divided into four key cellular processes such as glandular secretion, cell proliferation, smooth muscle contraction and neurotransmission. It is part of a group of hormones known as hypothalamus releasing factors which are hormones of hypothalmic origin and affect the release of pituitary hormones therefore the integration of the hormonal and nervous systems. It was discovered by Roger Guillemin who in 1977 won the Nobel Prize along with Andrew Schally for discoveries that laid the foundation for brain hormone research.