CXCL12 and neoplasm: This elevation may enhance the susceptibility of tumor cells to immune checkpoint blockade.752,753 Furthermore, radiotherapy induces the secretion of immune-suppressive cytokines and chemokines, including TGF-β, IL-6, and CXCL12, facilitating the recruitment of regulatory immune cells to tumors, such as MDSCs, regulatory T cells (Treg cells), and alternatively activated macrophages (M2).754 Overall, these findings provide a theoretical rationale for combining radiotherapy with immunotherapy.