Moreover, ZAP-70 expression was identified in a subset of other B cell malignancies, including, Follicular Lymphoma (FL), Mantle Cell Lymphoma (MCL), Hairy Cell Leukemia (HCL), and Diffuse Large B-cell Lymphoma (DLBCL) by western blotting, flow cytometry (14) and immunohistochemistry assessment (8), and in very rare cases of classic Hodgkin lymphoma (18). The gene discussed is ZAP70; the disease is hairy cell leukemia.