Abstract: This disclosure relates generally to methods and agents for assessing T-cell function and for predicting responses to therapy. More particularly, the present invention relates to methods and agents for detecting different forms of Eomesodermin (EOMES) in T-cells, which are useful for assessing the function of a T-cell, for assessing the immune function of a subject, for predicting the likelihood of response of a cancer patient to therapy including immunotherapy, for stratifying a cancer patient as a likely responder or non-responder to a therapy, and for managing treatment of a cancer patient.