In the present case, although the production of high-molecular-weight IGF-II from the tumor was not demonstrated, we considered her hypoglycemia to be attributable to NICTH because the patient had no other diseases that could have caused hypoglycemia (such as the aforementioned liver failure, adrenal failure, and insulinoma) and levels of IRI and C-peptide were low. This evidence concerns the gene IGF2 and liver failure.