The thymus is an important central immune organ that provides the microenvironment necessary for the development of T lymphocytes from hematopoietic stem cells. Thymic epithelial cells （TECs）， as one of the most critical components of the thymic microenvironment， play an important role in immune regulation. Thymic epithelial cells are mainly categorized into cortical epithelial cells and medullary epithelial cells， which mediate the positive and negative selection of thymocytes， respectively. From the perspective of the pathway of action， thymic epithelial cells mainly regulate thymocyte development through the secretion of cytokines， thymic hormones， or direct interaction with thymocytes. In this paper， the role of thymic epithelial cells in immunomodulation was reviewed.

Thymic epithelial cells, T lymphocytes, Immunomodulation