STAT3 and cholangiocarcinoma: Consistent with other researchers’ observation of a close association between activated COX-2/PGE2 and JAK2/STAT3 signaling pathways in prostate, lung cancers and cholangiocarcinoma [13–15], we discovered, in human CRC tissues, higher amount of COX-2 and pSTAT3, which significantly correlated with each other, and overall both were associated with higher degree of tumor invasiveness and metastasis.