The activated CD8+ T cells and NK cells in primary irradiated tumors migrate to metastases via blood circulation, thereby controlling secondary tumor growth at no‐irradiated sites.[71] However, the abscopal effect induced by RT alone is rare in preclinical and clinical practices, which may be caused by RT‐induced immunosuppressive mediators in primary tumors, such as TGF‐β and VEGF, into the circulation to exert systemic immunosuppressive effects. Here, TGFB1 is linked to neoplasm.