IL-11 mRNA A. and protein B. levels are significantly higher in ATC cell lines (ARO, FRO, 8305C, and sw579) than in differentiated thyroid carcinoma cell lines (KAT-5, KAT-10), as measured by quantitative RT-PCR and ELISA, respectively. After knocking down IL-11, the mRNA C. and protein D. levels of IL-11 in sw579 cells significantly decreased, as measured by quantitative RT-PCR and ELISA, respectively. After knocking down IL-11, the invasive and migratory abilities of sw579 cells significantly decreased, as assessed by transwell assay E. and wound-healing assay F. *P < 0.05, **P < 0.01, ***P < 0.001 relative to the controls (Student's t-test). Photomicrographs are at 100× magnification.