Ki-67 (protein)

Antigen KI-67 also known as Ki-67 or MKI67 is a protein that in humans is encoded by the MKI67 gene (antigen identified by monoclonal antibody Ki-67).

Function

Antigen KI-67 is a nuclear protein that is associated with and may be necessary for cellular proliferation. Furthermore, it is associated with ribosomal RNA transcription. Inactivation of antigen KI-67 leads to inhibition of ribosomal RNA synthesis.

Use as cell marker

The Ki-67 protein (also known as MKI67) is a cellular marker for proliferation. It is strictly associated with cell proliferation. During interphase, the Ki-67 antigen can be exclusively detected within the cell nucleus, whereas in mitosis most of the protein is relocated to the surface of the chromosomes. Ki-67 protein is present during all active phases of the cell cycle (G₁, S, G₂, and mitosis), but is absent from resting cells (G₀).

Antibody labeling

Ki-67 is an excellent marker to determine the growth fraction of a given cell population. The fraction of Ki-67-positive tumor cells (the Ki-67 labeling index) is often correlated with the clinical course of cancer. The best-studied examples in this context are carcinomas of the prostate, brain and the breast and nephroblastoma. For these types of tumors, the prognostic value for survival and tumor recurrence have repeatedly been proven in uni- and multivariate analysis.

Sukhoi Su-30MKI

The Sukhoi Su-30MKI (NATO reporting name: Flanker-H) is a twinjet multirole air superiority fighter developed by Russia's Sukhoi and built under licence by India's Hindustan Aeronautics Limited (HAL) for the Indian Air Force (IAF). A variant of the Sukhoi Su-30, it is a heavy, all-weather, long-range fighter.

Development of the variant started after India signed a deal with Russia in 2000 to manufacture 140 Su-30 fighter jets. The first Russian-made Su-30MKI variant was accepted into the Indian Air Force in 2002, while the first indigenously assembled Su-30MKI entered service with the IAF in 2004. Additional MKIs have been ordered to increase the total to 272. The IAF had 200 Su-30MKIs in service as of August 2014. The Su-30MKI is expected to form the backbone of the Indian Air Force's fighter fleet to 2020 and beyond.

The aircraft is tailor-made for Indian specifications and integrates Indian systems and avionics as well as French and Israeli sub-systems. It has abilities similar to the Sukhoi Su-35 with which it shares many features and components.