1 Department of Physiology, CIMUS, University of Santiago de Compostela, Santiago de Compostela, Spain; CIBER Fisiopatologia de la Obesidad y Nutrición (CIBERobn), Spain. Electronic address: m.lopez@usc.es.
2 Department of Physiology, CIMUS, University of Santiago de Compostela, Santiago de Compostela, Spain; CIBER Fisiopatologia de la Obesidad y Nutrición (CIBERobn), Spain; Galician Agency of Innovation (GAIN), Xunta de Galicia, Santiago de Compostela, Spain. Electronic address: ruben.nogueiras@usc.es.
López and Nogueiras introduce the peptide ghrelin and its physiological functions, including its roles in stimulating appetite and growth hormone release.