Recent evidence, indicates that T-cell receptor (TCR) triggering and T-cell activation are dynamic processes that involve various aspects of T-cell organization. In addition to the interaction between the TCR molecule and its ligand, T-cell activation depends on a combination of many other events involving coreceptor molecules, actin cytoskeleton and plasma membrane lipids. Altogether, these cell structures organize the formation of a specialized junction between the T cell and the antigen-presenting cell (APC), that plays a critical role in sustaining and amplifying TCR signalling.