MKI67 and neuroendocrine carcinoma: A mitotic count of <2 per 2 mm2 and/or a Ki-67 index <3% identifies NET G1, a mitotic count of 2 to 20 per 2 mm2 and/or a Ki-67 index of 3% to 20% identifies NET G2, and a mitotic count of >20 per 2 mm2 and/or a Ki-67 index >20% leads to an NEC definition (8).