Neuroendocrine protein 7B2 (SCG5)

Acts as a molecular chaperone for PCSK2/PC2, preventing its premature activation in the regulated secretory pathway. Binds to inactive PCSK2 in the endoplasmic reticulum and facilitates its transport from there to later compartments of the secretory pathway where it is proteolytically matured and activated.

Also necessary for cleavage of PCSK2 but doesn't seem to be involved in its folding. Plays a role in regulating pituitary hormone secretion.