Sharing calcium opens new avenues of signalling

A consequence of intracellular calcium signalling is that calcium released into the cytosol is extruded from the cell. New research shows that when the interstitial space is constricted, calcium extruded from one cell may increase levels of calcium in the surrounding medium sufficiently to activate calcium-sensing receptors on the surfaces of adjacent cells. Thus, the calcium that serves as an intracellular signal can also serve as an extracellular signal to recruit neighbouring cells.