C5AR1 and prostate cancer: It synergistically induces selective death of prostate cancer cells and augments the anticancer efficacy of the system.324 As a specific aptamer targeting complement C5a, AON-D21 can block the C5a/C5aR1 signal axis, effectively reducing the bone metastasis and tumor burden in lung cancer (Fig. S3).335 Research indicates that BMSCs are capable of migrating from the primary tumor site to the bone marrow, with the migration dependent on osteopontin (OPN).