CD27 and hairy cell leukemia: CD5, CD23, CD10, and CD27 in hair cells are usually negative or weakly expressed, whereas CD11c, CD103, CD123, and CD25 are positive.[1] One case of HCL with atypical immunophenotype of CD103 (−) and CD23 (+) admitted to our department was recently reported to discuss the clinical characteristics, diagnosis, differential diagnosis, treatment, and prognosis of HCL, and to review the literature.