After the release of the 2010 World Health Organization (WHO) classification, it was recognised that the neuroendocrine tumour (NET) category included well‐differentiated tumours with a Ki‐67 greater than 20% and therefore overlapped with the Ki‐67 range of neuroendocrine carcinoma (NEC), and exhibited a more aggressive course than Grade 1–2 (G 1–2) NET. The gene discussed is MKI67; the disease is neoplasm.