Subsequent updates by the European Neuroendocrine Tumor Society (ENETS) and the North American Neuroendocrine Tumor Society (NANETS) incorporated a Tumor-Node-Metastasis (TNM) staging system, mitotic count, and the Ki-67 index, allowing for a better evaluation of tumor aggressiveness, even from small biopsies [30,31,32]. This evidence concerns the gene MKI67 and neoplasm.