Del Giudice and coworkers have explored in detail the expression of CD123 in neoplastic cells derived from 59 patients with B-cell disorders with circulating hairy or villous lymphocytes: CD123 was expressed on hairy cell leukemia, but not on the variant form of hairy cell leukemia and splenic lymphoma with villous lymphocytes [32]. Here, IL3RA is linked to hairy cell leukemia.