Expression in Normal TissuesEdit
- Expressed in actively dividing/proliferating cells of all types. In other words, Ki-67 expression is seen in cells that are in any active phase of the cell cycle (G1, S, G2, and mitosis), but is not expressed in non-dividing/quiescent cells that are in G0 phase.
Expression in Neoplastic EntitiesEdit
Intermediate/Uncertain Malignant PotentialEdit
Expression in Non-Neoplastic EntitiesEdit
This antigen is typically NOT expressed by the following entities:
- Reactive, negative or atypical squamous epithelium of cervix 
Practical Uses / PanelsEdit
- Ki-67 index is used as a approximate indicator of proliferative activity in various tumors. Some tumors use strict Ki-67 index cutoffs for diagnosis, but many tumors do not have strict criteria. The Ki-67 index is the number of Ki-67 positive tumor cells per 100 tumor cells, expressed as a percentage.
- In the cervix, p16 can be used with Ki-67 (MIB-1) to differentiate between atrophy or reactive squamous epithelium (p16 focally + or negative, Ki-67 restricted to basal layer) from high-grade dysplasia (diffuse p16 +, Ki-67 diffuse +).