A mitotic count of <2 per 10 high-power fields (hpf) and/or a Ki-67 index <3% corresponds to NET G1, a mitotic count of 2–20/10 hpf and/or a Ki-67 index of 3%–20% to NET G2, and a mitotic count of >20/10 hpf and/or a Ki-67 index >20% to NEC (Table 1). This evidence concerns the gene MKI67 and neuroendocrine carcinoma.