Saikosaponin D has been demonstrated to inhibit proliferation and induce apoptosis of HCC SMMC‐7721 cells by downregulating cyclooxygenase 2 (COX‐2) expression and decreasing prostaglandin E2 production via inhibiting phosphor-signal transducer and activator of transcription 3/hypoxia inducible factor‐1α (p‐STAT3/HIF‐1α) pathway [262]. The gene discussed is STAT3; the disease is hepatocellular carcinoma.