Downregulation of SLAMF7 on primary myeloma and myeloma cell lines (MM1.S) after panobinostat treatment. (A) SLAMF7 expression on primary myeloma cells (n = 3 patients) before and after panobinostat treatment. Left bar diagram shows SLAMF7 expression as normalized MFI of panobinostat-treated vs untreated myeloma after 24, 48, and 72 hours of culture. Normalized MFI values were calculated as follows: MFIs 10 nM or 25 nM × 100/MFI untreated cells. The overlay histogram shows SLAMF7 expression after 48 hours of treatment with panobinostat at the indicated dose in 1 representative case. Shaded histograms show staining with anti-SLAMF7 mAb, and the white histogram shows staining with isotype control antibody. (B) SLAMF7 expression on MM1.S myeloma cells (n = 4 experiments) before and after panobinostat treatment in experiments performed analogous to panel A. (A-B) Values are mean ± SD. P values between indicated groups were calculated by using a paired Student t test. *P < .05; **P < .01; ***P < .001.