This study concludes that (a) SLC suppresses TNFα-induced MDA-MB-231 cell migration and invasion by inhibiting NF-κB-dependent MMP-9 expression, (b) SLC-derived costunolide inhibited serum or TNFα-induced MDA-MB-231 cell migration and invasion, (c) costunolide inhibited TNFα-induced NF-κB translocation resulting from the suppression phosphorylation and IκBα degradation (d) costunolide blocked TNFα-induced NF-κB transcription activity and TNFα-induced MMP-9 expression, and (e) costunolide decreased in vivo tumor growth and metastasis without weight loss (Figure 6). The gene discussed is NFKB1; the disease is neoplasm.