CD160 is a GPI-anchored protein with potential to be a useful cancer target10,11; it has been detected on endothelial cells of newly formed blood vessels in human colon carcinoma and mouse B16 melanoma but not in vessels of healthy tissues12,13 CD160 has been also shown to be aberrantly expressed on B cell malignancies such as B cell chronic lymphocytic leukaemia (B-CLL) and hairy cell leukaemia (HCL)14,15. Here, CD160 is linked to hairy cell leukemia.