In addition, neuroendocrine tumors are divided into well- or poorly differentiated by a Ki67 cut off of 20 % or a hematoxylin-eosin mitotic index of 20 mitoses per 2 mm2; however, the suggested cut offs for PHH3 are as low as four cells per 2 mm2 [27]. This evidence concerns the gene MKI67 and neuroendocrine neoplasm.