Figure 5: The levels of OPG after treatment with 1,25(OH)2D3, MTX, and 1,25(OH)2D3 plus MTX in RA patients. The RA patients’ PBMCs are treated with either anti-CD3/CD28, or 1,25(OH)2D3 and MTX at various concentrations, or the combination of 1,25(OH)2D3 and MTX (D2M2 group). There was no difference in OPG expression between the groups of 1,25(OH)2D3, MTX, and D2M2 and the group of anti-CD3/CD28 ( ).