CD38 expression is increased on MM and NK cells after cell surface desialylation. (A-B) MM cell lines H929, MM1S, and JJN3 were pretreated with either NEURA (A) or SIA (B) and stained for CD38 expression. (C) MNCs isolated from BMAs of afflicted patients were treated with SIA for 60 hours, after which CD38 expression was measured. n = 5 biological replicates (A-B), n = 6 primary samples (C). Data analyzed using Student’s paired t-test; graphs represent mean CD38 mean fluorescence intensity (MFI) + SEM. *P < .05; **P < .01; ***P < .001; ns, not significant.