Sanguinarine (1) is capable of significantly targeting ephrin type-B receptor 4 (EphB4) and hypoxia inducible factor-1α (HIF-1α) in breast cancer, inhibiting the activation of the downstream protein signal transducer and activator of transcription 3 (STAT3) in cells, blocking hypoxia-induced HIF-1α or STAT3 interacts, and downregulating the mRNA levels of its target genes, thus inhibiting breast cancer cell hyperplasia [12]. This evidence concerns the gene STAT3 and breast cancer.