Peptides are tiny messengers that cells use to communicate by binding to...

https://bravo-wiki.win/index.php/Why_Are_So_Many_Hormones_Peptides%3F_Exploring_the_Language_of_Cellular_Communication

Peptides are tiny messengers that cells use to communicate by binding to specific receptors. Researchers study how peptides interact with these receptors to understand signaling pathways, often measuring changes like cyclic AMP levels inside cells