(C) Pacs1-/- FOB cells were stimulated with 0.625 µM thapsigargin (black arrowhead) under Ca2+-free conditions to measure intracellular Ca2+ stores. Kinetic traces of four independent experiments are shown (Pacs1+/+ gray, Pacs1-/- pink) with the mean overlaid in bold (Pacs1+/+ black, Pacs1-/- red). 