Some studies have suggested that the cytoplasmic localization of TOB1 is required for its antiproliferative effect.14 In contrast, another study reported that the nuclear localization of TOB1 had antiproliferative activity.13 Prior studies have also noted the importance of phosphorylation of TOB1. 10, 12 Our tissue and cell studies demonstrated that in pancreatic cancer, TOB1 protein was mainly located in the cytoplasm, indicating that its antiproliferative effect may be independent of nuclear localization. The gene discussed is TOB1; the disease is familial pancreatic carcinoma.