Regulatory T‐cell development in the tumor microenvironment

Abstract Regulatory T (Treg) cells are required for maintaining self‐tolerance and preventing the development of autoimmune diseases. However, Treg cells are abundant in tumors and suppress antitumor immunity, contributing to tumor development and growth. Thus, the selective deletion of tumor‐infiltrating Treg cells is important for successful Treg cell‐targeted therapies, providing effective antitumor immunity without inducing deleterious autoimmune disorders. Advancements in sequencing technologies have exposed the diversity and heterogeneity of human Treg cells during activation and differentiation, further emphasizing the importance of understanding tumor‐infiltrating Treg cells for the development of Treg cell‐targeted therapies. This review provides an overview of the classification and function of Treg cells and summarizes recent knowledge on the activation and differentiation of Treg cells in the tumor microenvironment.