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CD34 molecule
Symbol CD34
External IDs OMIM142230 MGI88329 HomoloGene1343 GeneCards: CD34 Gene
RNA expression pattern
PBB GE CD34 209543 s at tn.png
More reference expression data
Species Human Mouse
Entrez 947 12490
Ensembl ENSG00000174059 ENSMUSG00000016494
UniProt P28906 Q64314
RefSeq (mRNA) NM_001025109 NM_001111059
RefSeq (protein) NP_001020280 NP_001104529
Location (UCSC) Chr 1:
208.06 – 208.08 Mb
Chr 1:
194.94 – 194.96 Mb
PubMed search [1] [2]

CD34 molecule is a cluster of differentiation molecule present on certain cells within the human body. It is a cell surface glycoprotein and functions as a cell-cell adhesion factor. It may also mediate the attachment of stem cells to bone marrow extracellular matrix or directly to stromal cells. CD34 is also the name for the human gene that encodes the protein.[1][2][3]


The CD34 protein is a member of a family of single-pass transmembrane sialomucin proteins that show expression on early hematopoietic and vascular-associated tissue.[4] However, little is known about its exact function.[5]

CD34 is also an important adhesion molecule and is required for T cells to enter lymph nodes. It is expressed on lymph node endothelia, whereas the L-selectin to which it binds is on the T cell.[6][7] Conversely, under other circumstances CD34 has been shown to act as molecular "Teflon" and block mast cell adhesion, or to facilitate opening of vascular lumens.[8][9] Regardless of their mode of action, under all circumstances CD34 and its relatives, podocalyxin and endoglycan, have been shown to facilitate cell migration.[10][11]

Tissue distribution[edit]

Cells expressing CD34 (CD34+ cell) are normally found in the umbilical cord and bone marrow as hematopoietic cells, a subset of mesenchymal stem cells, endothelial progenitor cells, endothelial cells of blood vessels but not lymphatics (except pleural lymphatics), mast cells, a sub-population dendritic cells (which are factor XIIIa-negative) in the interstitium and around the adnexa of dermis of skin, as well as cells in soft tissue tumors like DFSP, GIST, SFT, HPC, and to some degree in MPNSTs, etc. The presence of CD34 on non-hematopoietic cells in various tissues has been linked to progenitor and adult stem cell phenotypes.[12] It is important to mention that Long-Term Hematopoietic Stem Cells [LT-HSCs] in mice and humans are the hematopoietic cells with the greatest self-renewal capacity. Human HSCs express CD34 marker but mice HSCs do not express CD34 marker.

Clinical applications[edit]

CD34+ cells may be isolated from blood samples using immunomagnetic or immunofluorescent methods.

Antibodies are used to quantify and purify hematopoietic progenitor stem cells for research and for clinical bone marrow transplantation. However, counting CD34+ mononuclear cells may overestimate myeloid blasts in bone marrow smears due to hematogones (B lymphocyte precursors) and CD34+ megakaryocytes.

Cells observed as CD34+ and CD38- are of an undifferentiated, primitive form; i.e., they are multipotential hemopoietic stem cells. Thus, because of their CD34+ expression, such undifferentiated cells can be sorted out.

In tumors, CD34 is found in alveolar soft part sarcoma, preB-ALL (positive in 75%), AML (40%), AML-M7 (most), dermatofibrosarcoma protuberans, gastrointestinal stromal tumors, giant cell fibroblastoma, granulocytic sarcoma, Kaposi’s sarcoma, liposarcoma, malignant fibrous histiocytoma, malignant peripheral nerve sheath tumors, mengingeal hemangiopericytomas, meningiomas, neurofibromas, schwannomas, and papillary thyroid carcinoma.

A negative CD34 may exclude Ewing's sarcoma/PNET, myofibrosarcoma of the breast, and inflammatory myofibroblastic tumors of the stomach.

Injection of CD34+ hematopoietic Stem Cells has been clinically applied to treat various diseases including Spinal Cord Injury,[13] Liver Cirrhosis[14] and Peripheral Vascular disease.[15] Research has shown that CD34+ cells are relatively more in men than in women in the reproductive age among Spinal Cord Injury victims.[16]


CD34 has been shown to interact with CRKL.[17] It also interacts with L-selectin, important in inflammation.

See also[edit]


  1. ^ "Entrez Gene: CD34 CD34 molecule". 
  2. ^ Simmons DL, Satterthwaite AB, Tenen DG, Seed B (1 January 1992). "Molecular cloning of a cDNA encoding CD34, a sialomucin of human hematopoietic stem cells". J. Immunol. 148 (1): 267–71. PMID 1370171. 
  3. ^ Satterthwaite AB, Burn TC, Le Beau MM, Tenen DG (April 1992). "Structure of the gene encoding CD34, a human hematopoietic stem cell antigen". Genomics 12 (4): 788–94. doi:10.1016/0888-7543(92)90310-O. PMID 1374051. 
  4. ^ Nielsen JS, McNagny KM (2008). "Novel functions of the CD34 family". J of Cell Science 121 (Pt 22): 3682–3692. doi:10.1242/jcs.037507. PMID 18987355. 
  5. ^ Furness SG, McNagny K (2006). "Beyond mere markers: functions for CD34 family of sialomucins in hematopoiesis". Immunol. Res. 34 (1): 13–32. doi:10.1385/IR:34:1:13. PMID 16720896. 
  6. ^ Berg EL, Mullowney AT, Andrew DP, Goldberg JE, Butcher EC (February 1998). "Complexity and differential expression of carbohydrate epitopes associated with L-selectin recognition of high endothelial venules". Am. J. Pathol. 152 (2): 469–77. PMC 1857953. PMID 9466573. 
  7. ^ SSuzawa K, Kobayashi M, Sakai Y, Hoshino H, Watanabe M, Harada O, Ohtani H, Fukuda M, Nakayama J (July 2007). "Preferential induction of peripheral lymph node addressin on high endothelial venule-like vessels in the active phase of ulcerative colitis". Am. J. Gastroenterol. 102 (7): 1499–509. doi:10.1111/j.1572-0241.2007.01189.x. PMID 17459027. 
  8. ^ Drew E, Merzaban JS, Seo W, Ziltener HJ, McNagny KM (2005). "CD34 and CD43 inhibit mast cell adhesion and are required for optimal mast cell reconstitution". Immunity 22 (1): 43–57. doi:10.1016/j.immuni.2004.11.014. PMID 15664158. 
  9. ^ Strilić B, Kucera T, Eglinger J, Hughes MR, McNagny KM, Tsukita S, Dejana E, Ferrara N, Lammert E (2009). "The molecular basis of vascular lumen formation in the developing mouse aorta". Dev Cell 17 (4): 505–15. doi:10.1016/j.devcel.2009.08.011. PMID 19853564. 
  10. ^ Blanchet MR, Maltby S, Haddon DJ, Merkens H, Zbytnuik L, McNagny KM (2007). "CD34 facilitates the development of allergic asthma". Blood 110 (6): 2005–12. doi:10.1182/blood-2006-12-062448. PMID 17557898. 
  11. ^ Maltby S, Wohlfarth C, Gold M, Zbytnuik L, Hughes MR, McNagny KM (2010). "CD34 Is Required for Infiltration of Eosinophils into the Colon and Pathology Associated with DSS-Induced Ulcerative Colitis". Am J Path 177 (3): 1244–54. doi:10.2353/ajpath.2010.100191. PMC 2928958. PMID 20696776. 
  12. ^ Sidney LE, Branch MJ, Dunphy SE et al. (2014) Stem Cells.Concise review: Evidence for CD34 as a common marker for diverse progenitors. DOI: 10.1002/stem.1661. PMID 24497003.
  13. ^ Srivastava A, Bapat M, Ranade S, Srinivasan V, Murugan P, Manjunath S, Thamaraikannan P, Abraham S (2010). "Autologous Multiple Injections of in Vitro Expanded Autologous Bone Marrow Stem Cells For Cervical Level Spinal Cord Injury - A Case Report". Journal of Stem Cells and Regenerative Medicine. 
  14. ^ Terai S, Ishikawa T, Omori K, Aoyama K, Marumoto Y, Urata Y, Yokoyama Y,Uchida K, Yamasaki T, Fujii Y, Okita K, Sakaida I (2006). "Improved liver function in patients with liver cirrhosis after autologous bone marrow cell infusion therapy". Stem Cells 24 (10): 2292–8. doi:10.1634/stemcells.2005-0542. PMID 16778155. 
  15. ^ Subrammaniyan R, Amalorpavanathan J, Shankar R, Rajkumar M, Baskar S, Manjunath SR, Senthilkumar R, Murugan P, Srinivasan VR, Abraham S (September 2011). "Application of autologous bone marrow mononuclear cells in six patients with advanced chronic critical limb ischemia as a result of diabetes: our experience". Cytotherapy 13 (8): 993–9. doi:10.3109/14653249.2011.579961. PMID 21671823. 
  16. ^ Dedeepiya V, Rao Y Y, Jayakrishnan G, Parthiban JKBC, Baskar S, Manjunath S, Senthilkumar R and Abraham S (2012). "Index of CD34+ cells and mononuclear cells in the bone marrow of Spinal cord Injury patients of different age groups- A comparative analysis". Bone Marrow Research. 
  17. ^ Felschow, D M; McVeigh M L; Hoehn G T; Civin C I; Fackler M J (Jun 2001). "The adapter protein CrkL associates with CD34". Blood (United States) 97 (12): 3768–75. doi:10.1182/blood.V97.12.3768. ISSN 0006-4971. PMID 11389015. 

Further reading[edit]

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