What is CD34?

CD34 is a protein normally produced by the cells inside blood vessels, immune cells, and supporting cells. It can also be produced by tumour cells. Pathologists use a test called immunohistochemistry to see cells producing this protein under the microscope.

Normal types of cells that produce CD34

  • Endothelial cells – These are the cells that line the inside of blood vessels throughout the body.
  • Hematopoietic progenitor cells – These are immature cells that will later become part of the immune system.
  • Fibroblasts – Fibroblasts are found all over the body. They are support cells that help hold the body together. They also help heal the body after injury.

Non-cancerous tumours that produce CD34

Types of cancers that produce CD34


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