Table 2.

Modes of action of Tregs.

Target	Modes of actions	Reference
Effector T cells	IL-2 consumption to inhibit clonal expansion
	Suppressive cytokine secretion (TGFβ, IL-10, IL-35)	(38)
	Hydrolysis of adenosine phosphates via CD39, CD73	(39)
	Direct cell killing via perforin/granzyme	(40)
Dendritic cells/antigen-presenting cells	Blocking CD80/86 through CTLA4	(36)
	Inhibition of autophagy through CTLA4	(41)
	Indoleamine 2,3-dioxygenase induction	(37)
Hair follicle stem cells	Promoting proliferation and differentiation	(48)
Muscle progenitor cells	Amphiregulin-mediated differentiation	(43)
Adipocytes	Maintain insulin tolerance through IL-10	(23)