Give a stream of consciousness and then the final answer. Ghrelin (pronounced / rln /), the "hunger hormone", also known as lenomorelin (INN), is a peptide hormone produced by ghrelinergic cells in the gastrointestinal tract which functions as a neuropeptide in the central nervous system. Besides regulating appetite, ghrelin also plays a significant role in regulating the distribution and rate of use of energy.

Based on this passage, which hormone plays a significant role in appetite stimulation?
To answer this question, we should know that: Ghrelin (pronounced / rln /), the "hunger hormone", also known as lenomorelin (INN), is a peptide hormone produced by ghrelinergic cells in the gastrointestinal tract which functions as a neuropeptide in the central nervous system.
So, the final answer is Ghrelin.