The chemopreventive capacity of paeonol relies on its multifaceted anticancer mechanisms by directly inhibiting cell growth and proliferation, inducing apoptosis, suppressing invasion and metastasis (MMP-2 and-9, VEGF and HIF-1α), and inhibiting the TLR4/NF-κB/STAT3/MAPK/PI3K/AKT/CHOP pathways to inhibit cancer development and progression. This evidence concerns the gene STAT3 and cancer.