Figure 3: Similar BCR signaling but possibly enhanced TLR9 signaling in the healthy sibling. (a) Calcium mobilization upon triggering of the BCR using IgM F(ab′)2 fragments in freshly isolated PBMCs. (b) CD40 surface expression as measured by flow cytometry. (c) TLR9 B-cell expression (c ii) and function (c iii). Light grey line indicated isotype indicated dark grey, TLR9 (c i). Bars represent means ± standard error of the mean.