T cells bearing receptors with high affinity for self-antigens are responsible for the
generation of autoimmune diseases. Therefore, potentially autoreactive thymocytes must be
eliminated or inactived in normal individuals. Induction of tolerance in thymocytes occurs by
a process of negative selection controlled by the thymic stroma, and in particular by thymic
dendritic cells (DCs). Here, Carlos, Ardavi´ n reviews current knowledge on thymic DCs and
their role in negative selection.