MKI67 and digestive system neuroendocrine neoplasm: According to World Health Organization (WHO) 2019, High-Grade Gastroenteropancreatic neuroendocrine neoplasms (H-NENs) comprehend tumors with a Ki-67 index >20% distinguished in NET-G3, when Well-Differentiated (WD), or NEC-G3, when Poorly-Differentiated (PD) [1].