PTGS2 and lung cancer: Activation of c-Src, often linked also with an increased activity of MAP kinases, can indeed impact both structural and signaling functions of cell-to-cell junctions, including GJs, AJs or TJs, but it has been also implicated in TCDD-mediated upregulation of COX-2 [229], a key enzyme producing prostaglandins which may contribute to tumorigenesis including lung cancer [231,232].