It is therefore relevant that the original Fog-1 was obtained from human-mouse heterohybridoma cells following fusion of Epstein-Barr virus-transformed B lymphocytes with the mouse myeloma line X63-Ag8.653 [10] whereas transfected YB2/0 rat myeloma cells were used for the production of both recombinant Fog-1 G1 and G1Δnab. The gene discussed is ZFPM1; the disease is plasma cell myeloma.