CD135 (flt3/flk2) Antibodies

The CD135 antigen, also called FLT3 or FLK2 or STK1, is an integral transmembrane glycoprotein of 130 kDa to 150 kDa, which belongs to the class III receptor tyrosine kinase (RTK) family. These receptors directly bind extracellular ligands and transduce regulatory signals through intracytoplasmic tyrosine kinase activity. The CD135 antigen is expressed on myelomonocytic and primitive B cell progenitors. On normal bone marrow cells, expression of CD135 can be found on CD34‑positive as well as CD34‑negative cells. Most of the CD34bright, CD135‑positive cells co-express CD117 at high levels. They may represent early cycling, not quiescent stem cells. CD135‑positive cells in the CD34 low and CD34‑negative populations do not co-express CD117 molecule and may represent B-lymphoid precursors.