Fig. (5) Double immunoenzymatic labelling of bone marrow samples; FOXP1 brown and CD138 blue. As indicated by the top four panels the majority of pre-malignant and malignant CD138⁺ plasma cells lacked expression of the FOXP1 protein, although there were many CD138-FOXP1⁺ cells in this tissue. The detection of >30% FOXP1⁺/CD138⁺ cells was restricted to two MM cases, one from Oxford (bottom left) and the other from Zagreb (bottom right).