MKI67 and neuroendocrine carcinoma: As per WHO classification, neuroendocrine tumor (NET) is classified as NET G1 (well‐differentiated, mitotic rate < HPFs and/or Ki67 index < 3%), NET G2 (well‐differentiated, mitotic rate 2–20 HPFs and/or Ki67 index 3–20%), G3 (well‐differentiated, mitotic rate > 20 HPFs and/or Ki67 index > 20%), NEC (Poorly differentiated, mitotic rate > 20 HPFs and/or Ki67 index > 20%), and mixed neuroendocrine‐non‐neuroendocrine neoplasm (MiNEN) [9].