Ki-67 (MKI67)
Ki-67 is a protein present only in cells that are dividing, so the share of tumour cells that stain for it is a direct read of how fast the cancer is growing.
Overview
MKI67 encodes a large nuclear protein expressed through the active phases of the cell cycle and absent in resting (G0) cells. The Ki-67 labelling index by immunohistochemistry (antibody MIB-1 on paraffin sections) grades neuroendocrine tumours in the WHO classification and is read in breast cancer as a proliferation marker; the abemaciclib adjuvant approval of 2021 used a Ki-67 score of at least 20 percent as an entry criterion before the label was broadened in 2023. It is a readout, not a drug target: no approved medicine binds Ki-67.
- Target · the protein and the cell it sits on
- Drug · antibody, small molecule, cell or radioligand
- Effect · signal, damage or kill
In plain words · Ki-67 is a protein present only in cells that are dividing, so the share of tumour cells that stain for it is a direct read of how fast the cancer is growing.
- 1 · What it is
Ki-67 is a protein present only in cells that are dividing, so the share of tumour cells that stain for it is a direct read of how fast the cancer is growing.
- 2 · What goes wrong in cancer
Ki-67 coats the surface of mitotic chromosomes and keeps them from clumping; its level rises through S, G2 and M phase and falls to nothing in quiescent cells, which is why the stained fraction tracks proliferation.
- 3 · How drugs use it
No product in this corpus aims at Ki-67 (MKI67) yet. Drugs bind the molecule precisely: to switch it off, flag the cell for the immune system, or deliver a payload.
External identifiers
What a pathology or genomic report can say about this target, each with the thresholds approvals use.
Biology
Ki-67 coats the surface of mitotic chromosomes and keeps them from clumping; its level rises through S, G2 and M phase and falls to nothing in quiescent cells, which is why the stained fraction tracks proliferation.
- Breast cancer (proliferation index)
- Neuroendocrine tumours (WHO grade)
- Lymphomas and gliomas (proliferation index)
Latest papers
topQuery for this target: (TITLE:"Ki-67" OR ABSTRACT:"Ki-67" OR TITLE:"MKI67" OR ABSTRACT:"MKI67" OR TITLE:"Ki67" OR ABSTRACT:"Ki67" OR TITLE:"MIB-1" OR ABSTRACT:"MIB-1" OR TITLE:"marker of proliferation Ki-67" OR ABSTRACT:"marker of proliferation Ki-67") AND (cancer OR tumor OR tumour OR oncology OR carcinoma OR lymphoma OR leukemia OR leukaemia OR myeloma OR sarcoma OR melanoma OR glioma). Results are unfiltered search hits about Ki-67 (MKI67), not a curated reading list.
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