Anti-CD38 Ab restores T-cell response. (A) Proliferation of T cells stimulated by anti-CD2/CD3/CD28 beads (T:Bead ratio of 1:1) in the absence or presence of SAR anti-CD38 Ab (1 μg/mL) for 6 days was measured with CFSE dilution assay. (B-D) After CD14⁺ monocytes were stimulated with recombinant RANKL and M-CSF for 7 days, SAR anti-CD38 Ab was added for 7 days, and cells were examined for HVEM by flow cytometry (B), western blotting (C), and IDO1 by real-time qRT-PCR (D). *P < .05; **P < .001; by unpaired 2-sided Student t test.