Provided herein are methods for treating a subject afflicted with a cancer, comprising administering to the subject a TIM3 agonist (e.g., an anti-TIM3 antibody), alone or in conjunction with another immune checkpoint inhibitor (e.g., a PD-1 antagonist), wherein the subject is identified as having a high frequency of TIM3 positive cells (e.g., on the tumor infiltrating inflammatory cells) or soluble TIM3 in peripheral blood. Also provided are methods for assessing the efficacy of a treatment comprising a TIM3 antagonist in a subject afflicted with a cancer, comprising measuring the frequency of TIM3 (and optionally PD-1) positive cells in certain populations of cells and/or the soluble TIM3 in peripheral blood of the subject, wherein a high frequency of TIM3 (and optionally PD-1) positive cells and/or the subject's peripheral blood titer of soluble TIM3 is indicative of the response to the treatment.
