Figure 1. Action mechanism of the combination therapy.

Ionizing irradiation (electron beam) induces apoptosis and necrosis of dividing tumor cells. Heat shock protein 70 (HSP70) and high mobility group box-1 protein (HMGB1), over expressed in these cells, are released, which trap intravenously injected circulating eMIP. eMIP/HSP70 and eMIP/HMGB1 complexes activate immune cells such as natural killer (NK) cells, CD4⁺ and CD8⁺ T cells, directly or indirectly, which eradicate tumor cells that may evade the treatments and those distal to the target sites. Dendritic cells (DC) may also play a role to activate NK cells and T cells. The same mechanisms could be elicited with other forms of ionizing radiation such as photons (X-rays), since no difference has been demonstrated in the biological effectiveness of the different forms of ionizing radiation.