Gastroenteropancreatic (GEP) neuroendocrine neoplasms (NEN) with a Ki67 proliferation index above 20% are a heterogeneous group of rare, highly malignant neoplasms associated with a poor prognosis [1] Immunohistochemically assessed tumour expression of synaptophysin and/or CgA is mandatory for the NEN diagnosis. Here, MKI67 is linked to neoplasm.