SLT-1 binding by malignant B cells, breast carcinoma cells and HPC. Representative views from the flow cytometric detection of SLT-1 receptors on follicle center lymphoma grade I (A), multiple myeloma plasma cells (B), and breast carcinoma (C). The binding of FITC-SLT-B is shown in relation to anti-CD19 labeling (a pan-B–cell marker) for the lymphocyte gate in (A) or against B-B4 (plasma cell marker) for BM cells in (B) and against the combined expression of Ber-EP4 and M38 (MUC1) for a breast cancer biopsy (C). Dual-positives are shown in the upper right quadrant (A and C) or as a boxed area (B).