(E) Wdr37+/+ and Wdr37−/− splenocytes were labeled with Indo-1, stained for cell surface markers to identify FOB cells, and stimulated with the indicated amounts of anti-IgM (black arrowhead). Normalized traces from three (2.5 mcg/ml anti-IgM) or four independent experiments (10 mcg/ml and 5 mcg/ml anti-IgM) are shown (Wdr37+/+ gray, Wdr37−/− pink). Mean Ca2+ flux for each genotype is overlaid in bold (Wdr37+/+ black, Wdr37−/− red). 