Other than MM, multiple B cell malignancies such as hairy cell leukemia, chronic lymphocytic leukemia and mantle cell lymphoma frequently express surface FcRH5 on malignant cells23,24,44, broadening the spectrum of hematological malignancies amendable to immunotherapy with FcRH5 CAR-T cells. The gene discussed is FCRL5; the disease is hairy cell leukemia.