Expression of WASP in human cell lines. Western blot analysis of lysates from various hematopoietic cell lines (HL-60, K562, HEL, MEG01, Jurkat, normal IL-2–dependent T-cell line, normal B-LCL, and a B-LCL from a WAS patient with the classic phenotype) and 2 nonhematopoietic cell lines (293 and SK HEP1). All hematopoietic cell lines express WASP, with the exception of the B-LCL derived from a WAS patient. Nonhematopoietic cell lines do not express WASP.