Chromogranin A (CgA) is a dense core vesicle-associated protein and, therefore, represents a specific marker of neuroendocrine cells and tumours including pheochromocytomas. CgA has already been investigated for its immunogenic properties. Importantly, in vitro studies demonstrated the presence of naturally occurring CgA-specific cytotoxic T cells in patients with neuroendocrine cancers. Therefore, it is worthwhile to investigate the potential role of CgA as tumour antigen in pheochromocytoma. Depending on the results of these ongoing in vitro and in vivo studies, a clinical application may arise in the near future.