CXCL12 and thyroid gland undifferentiated (anaplastic) carcinoma: Treatment of anaplastic thyroid carcinoma cells with SDF-1 induces proliferation, which is blocked by the specific CXCR4 antagonist AMD3100 and by CXCR4 RNA interference, and AMD3100 effectively reduces tumor growth in nude mice inoculated with different anaplastic thyroid carcinoma cells (13).