Meanwhile, radiation exposure may also facilitate the recruitment of immunosuppressor cell populations to the tumor site such as regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSCs) through secreting specific chemokines (C-C motif chemokine ligand 2, C-C motif chemokine ligand 22, C-X-C motif chemokine ligand 1, etc) and cytokines (transforming growth factor-β, interleukin-10 (IL10), etc), which could potently block T cell activation and inhibit their effector function. Here, IL10 is linked to neoplasm.