Ki-67 immunohistochemistry (IHC) is a technique used to assess the proliferation rate of cells in breast cancer tissues.

Ki-67 is a protein that is present during active phases of the cell cycle (but absent in resting cells), making it a marker for cell proliferation. IHC staining for Ki-67 involves applying an antibody that binds to the Ki-67 protein in the nucleus, which is then visualized using a chromogen.

The staining is scored based on the percentage of tumor cells showing nuclear staining, with a higher percentage indicating a higher proliferation rate. This information is important for evaluating the aggressiveness of the cancer and can influence treatment decisions, such as the need for chemotherapy.

PAIKON for IHC Ki67 testing is currently availible as RUO product for microscopic and whole slide images.