CD38 and systemic lupus erythematosus: Similarly, we observed a negative correlation between the frequency of CD27+CD38− memory B cells with the frequencies of IL-35+ B cells (P = 0.0025, r = −0.4313; Fig. 5B) and IL-10+ B cells (P = 0.0016, r = −0.4480; Fig. 5C) in the SLE patients.