The present invention provides compositions and methods useful for promoting or reducing T-cell trafficking to a target tissue. Also provided are compositions and methods useful for promoting or inhibiting antigen-presenting cell (APC) activation. The invention is related to discovery of functional characteristics of TIM-3, a molecule that is preferentially expressed on the surface of Th1 cells. The methods are useful for treating disorders including cancer, infectious disease, allergy, asthma, and autoimmune disease.