IL-24 decreased mRNA levels of BLIMP1, IRF4, BCL6, and IL-10 and stimulated mRNA levels of PAX5 in GC B cells. Cells were cultured for 3 days with IL-2 + IL-10 + CD40L and IL-24 was added (black histograms) or not (white histograms) at day 3 then RNA was extracted after 1 or 3 more days for qPCR analysis. One hundred is the arbitrary value for unstimulated GC B cells at day 0 (n = 7 for IL-10 and n = 5 for the other transcripts).