Provided herein are compositions and methods for treating cancer. The compositions include a modified T cell comprising a nucleic acid encoding a calcium translocating channelrhodopsin (CatCh) polypeptide. The methods comprise administering to the subject with cancer one or more modified T cells comprising a nucleic acid encoding a calcium translocating channelrhodopsin (CatCh) polypeptide and exposing the one or more modified T cells in the subject to a visible light source.
