STAT3 and cancer: As a key cytokine linked to inflammation-associated cancer, IL6 is implicated in the facilitation of angiogenesis, tumorigenesis and progression by complicated mechanisms, such as increasing expression of invasion-related genes (Twist and MMP-1) and anti-apoptotic factors (Bcl-2 and Bcl-xL), and activation of PI3K, ERK, and STAT3 signaling pathway [44, 45].