 The study investigates how T cells maintain a high and robust Ca2 plus signal during immunological synapse formation, which is necessary for their proliferation and activation. It proposes that mitochondria relocation and accumulation of plasma membrane Ca2 plus ATPase and sarcoplasmic endoplasmic reticulum calcium ATPase pumps at the immunological synapse contribute to this, while also uncovering new mechanisms for generating Ca2 plus oscillations important for efficient T cell activation. This article was authored by Martin Peglow, Barbara A. Neemeyer, Marcus Hoth, and others.