May play an important regulatory role in corticotrophs.
Subcellular locations: Endoplasmic reticulum, Golgi apparatus, Cytoplasmic vesicle, Secretory vesicle lumen
Found in the lumen of secretory vesicles (dense core vesicles, DCV). However, seems to be retained intracellularly and not secreted.
Pancreas. Found in alpha, beta and delta cells in the pancreatic islets.