CD103 (EP206)

CD103 is an integrin subunit, αE, encoded by the ITGAE gene on chromosome 17.2 CD103 is expressed in almost all cases of hairy cell leukemia (HCL) and absent in the majority of other B-cell neoplasms with an exception to splenic marginal zone lymphoma, in which rare cases express CD103.1,2 CD103 has been found in mononuclear cells in the interfollicular area of lymph nodes and in intraepithelial cells in the overlying mucosa located primarily toward the basal layer of the tonsil.2 The high sensitivity of anti-CD103 for hairy cell leukemia makes this marker valuable when distinguishing from other B-cell neoplasms.