HCCLM3 cells (human hepatocellular carcinoma cells) were used to verify the relationship between miRNA-126-5p and TDO2 targeting, so as to explore the effect of miRNA-126-5p-based TDO2 targeting on the invasion, migration, and apoptosis of liver cancer cells and further study the underlying mechanism. The gene discussed is TDO2; the disease is liver cancer.