TXNIP and pancreatic insulinoma: It is also interesting to note the effect of metformin on Txnip, with metformin totally abrogating its expression in both cell lines, which is consistent with previous reports suggesting that metformin inhibits Txnip expression in human hepatocellular carcinoma HepG2 and cervical cancer HeLa cells [32], as well as rat insulinoma INS-1E beta-cells [51].