CSF1 and neoplasm: At the same time, some studies suggested that combining radiotherapy with cytokines and/or chemokines, as well as PD-1 and CTLA-4 blockade, could reverse CD8+ T cells exhaustion, inhibited myeloid-derived suppressor cells, polarized M2 macrophages, and reduced colony-stimulating factor-1 levels and transforming growth factor β, thereby overcoming tumor radioresistance to some extent [36–41].