Fig. 1. BOB.1/OBF.1 protein levels are regulated in germinal center B cells. RNA and protein extracts were prepared from purified CD38^– and CD38⁺ human tonsillar B cells. (A) BOB.1/OBF.1 expression levels were determined by quantitative real time PCR. CD38 was used as a positive control for the transcriptional regulation, PBGD was used for standardization. (B) Detection of BOB.1/OBF.1 protein levels by immunoblotting. Ramos B cells were used as positive control, RelA was used as a loading control.