(C) Pacs1+/+ and Pacs1−/− FOB cells were labeled with Indo-1 and stimulated in Ca2+ free buffer with 5 mcg/ml anti-IgM (black arrowhead) to assess ER Ca2+ efflux. Then, 2 mM Ca2+ was added back to assess SOCE. Kinetic traces normalized to baseline from three independent Pacs1+/+ and Pacs1−/− pairs are shown with the mean Ca2+ flux overlaid in bold. 