CD40 and systemic lupus erythematosus: The results are substantially superior concerning the CD40 MFI: the intensity of CD40 expression on B cells under the influence of the conditioned medium of MSCs was significantly decreased compared to the control group of B cells in healthy individuals (114.70 ± 16.91 vs. 124.94 ± 19.23; p = 0.0020), as well as in patients with SLE (104.89 ± 22.04 vs. 113.45 ± 22.48; p = 0.0008) (Figure 5B(a)).