Compositions for cancer therapy using mutant light molecules with increased affinity to receptors

Methods and compositions are disclosed to target tumor cells with embodiments of the LIGHT proteins linked fused or conjugated to a targeting agent. These compositions bind to both human and mouse receptors with affinity sufficient to conduct preclinical and clinical trials, and with increased affinity as compared to the wild type human LIGHT protein. The targeting of embodiments of LIGHT to tumor cells reduces tumor growth and reduces metastases.