Based on accumulating evidence, phytochemicals interfere with various intracellular mechanisms in many types of cancer, including the induction of apoptosis, the arrest of cell cycle progression, the blockade of transcription factors, such as NF-κB, the induction of oxidative stress, the suppression of MMP activity, and the inhibition of signal transduction pathways, such as the Akt, VEGF, Wnt, and STAT3 signaling pathways [21,55]. Here, STAT3 is linked to cancer.