Chromogranin B (CHGB), a member of the granin family of acidic secretory proteins, is primarily localized within secretory vesicles of neuroendocrine and neuronal cells. It is co-stored and released alongside neurotransmitters, hormones, and peptides, playing a critical role in granulogenesis, hormone packaging, and regulated secretion. CHGB shares structural and functional similarities with chromogranin A (CHGA), though it exhibits distinct tissue-specific expression patterns. It serves as a precursor for bioactive peptides like secretolytin, which may modulate innate immunity and microbial defense.
CHGB antibodies are widely used as immunohistochemical markers to identify neuroendocrine tumors (NETs), such as pheochromocytomas, paragangliomas, and neuroblastomas. Their diagnostic utility stems from CHGB's consistent presence in dense-core secretory granules, even in tumors with low CHGA expression. Beyond diagnostics, these antibodies facilitate research into neuroendocrine system dynamics, vesicular trafficking, and secretory pathway regulation. Recent studies also explore CHGB's potential role in neurodegenerative diseases and cardiovascular disorders, linked to its interaction with amyloidogenic proteins and vasoregulatory peptides. However, interpretation requires caution due to cross-reactivity risks and variable expression across neuroendocrine subtypes.