A rationale for these observations was provided by results from in vitro experiments (58) that showed that conditioned medium containing insulin secreted from Mif−/− pancreatic islets had lower activity than conditioned medium with insulin produced by wild-type islets, as demonstrated by reduced insulin signaling (AKT phosphorylation) and glucose uptake in a human liver carcinoma cell line (Hep G2 cells). This evidence concerns the gene INS and hepatocellular carcinoma.