Sesamin exerted its effects on SP cells. Sesamin significantly decreased SP cells fraction in a dose-dependent manner (A). Sesamin reduced the tumor-sphere formation ability of SP cells (B). Sesamin reduced the invasion capacity of CSCs (C). Sesamin inhibited colony formation of SP cells from SGC-996 and GBC-SD (D). *p < 0.05 vs. control group. Ses: sesamin.