IL-6 signals through the Janus-activated kinase/signal transducers and activators of transcription 3 (JAK/STAT3), mitogen-activated protein kinase/extracellular-signal regulated kinase1/2 (MAPK/ERK1/2), and phosphatidylinositol 3-kinase/Akt (PI3K/Akt) pathways, all of which are implicated in cancer and metastasis [14]. Here, STAT3 is linked to cancer.