MKI67 and carcinoid tumor: They can also be graded by assessing the mitotic activity or Ki-67 immunolabeling index; Grade 1 tumours (carcinoids) display <2 mitoses/10 high power fields or <2%Ki-67 index and Grade 2 tumours (“atypical carcinoids”) have mitotic counts of 2–20/10 high power fields or 3–20 % Ki-67 index [17].