RT combined with CAR-T cells can stimulate the production of chemokines by immune cells (such as macrophages and dendritic cells), endothelial cells, and even the tumor cells themselves, including C-C motif chemokine ligand 2 (CCL2) and C-X-C motif ligand 9 (CXCL9). The gene discussed is CCL2; the disease is neoplasm.