"The thymus is a specialized primary lymphoid organ of the immune system. Within the thymus, T cells or T lymphocytes mature. T cells are critical to the adaptive immune system, where the body adapts specifically to foreign invaders. The thymus is composed of two identical lobes and is located anatomically in the anterior superior mediastinum, in front of the heart and behind the sternum."@en . . . "Thymus"@en . . "274"^^ . . "Thymus+gland"@en . "1273"^^ . "A10.549.750" .