Provided herein are methods of activating immune response and/or treating cancer in a patient comprising administering to the patient a Gal3:TIM-3 inhibitor that interferes with the interaction between Gal3 and TIM-3, where said inhibitor is administered in an amount sufficient to activate immune response. Also provided are a humanized anti-Gal3 antibodies that can block the interaction between Gal3 and TIM3 and methods of using the anti-Gal3 antibody to treat cancer. Methods for determining if a patient's cancer is suitable for treatment with a Gal3:TIM-3 inhibitor and methods for selecting compounds that can block interaction between Gal3 and TIM-3, activating immune response and/or treating cancer are also provided.
