A potential limitation of STING agonists when used in combination with radiation is the radiation-associated recruitment of MDSCs that confer radiation resistance.87 MDSCs in the TME have been implicated in poor cancer patient prognosis, metastatic disease and immunotherapy resistance.52,104 Activation of type I IFN signaling might be one of the mechanisms recruiting these immunosuppressive cells within the TME.52,87 To limit MDSC recruitment a CCR2 antibody could be used since CCR2 is an MDSC attractant, and CCR2 inhibition has been shown to overcome immunosuppressive radiation effects.87 This evidence concerns the gene CCR2 and metastatic neoplasm.