STAT3 and head and neck cancer: Recently a relevant role of the transcription factor Signal Transducer and Activator of Transcription 3 (STAT3) in promoting EMT has been proposed.67 The aberrant expression of interleukin 6 (IL-6) and its activation of STAT3 have been correlated with the development and progression of carcinomas68 and in particular with increased metastatic potential and poor outcome in epithelial tumors.69 IL-6-STAT3 signaling promotes the initiation of EMT and the acquisition of mesenchymal features in breast and head and neck cancers, by inducing the expression of Twist and Snail.