In tumor cells, CASP8 induces apoptosis and inhibits proliferation [122] and metformin was found to increase CASP8 expression in A498 renal carcinoma cells at 7.5 mmol/L after 24 h [123] as well as in several pancreatic cancer cell lines at 30.0 mmol/L in vitro [124]. This evidence concerns the gene CASP8 and neoplasm.