【Abstract】Objective To determine the expression of zinc finger transcription factor GATA6 in insulinoma and its relationship with the proliferation and apoptosis of inslulinoma cells. Methods Tumor tissue and adjacent normal tissue specimens of 3 cases of insulinoma were collected from Jan. 2009 to Sep. 2014 in the Sixth People’s Hospital Affiliated to Shanghai Jiaotong University. Expression of GATA6 in the insulinoma and para-insulinoma tissue was evaluated by Western blotting. In addition, normal pancreas tissues of 2 cases were collected, and immunofluorescence staining was employed to detect the expression and localization of GATA6 in insulinoma and normal pancreatic tissues. Mouse insulinoma MIN6 cells were transfected by small interference RNA (siRNA) interference against GATA6, and then cell cycle and apoptosis were measured by flow cytometry. Results GATA6 was significantly highly expressed in the insulinoma than in para-insulinoma (P＜0.05). Immunofluorescence staining showed that normal islet structure had been disrupted in inulinoma tissue, and GATA6 was mainly localized in the nucleus of insulinoma cells and highly and extensively expressed in insulinoma tissue, and mildly in normal pancreatic islet β cells. After siRNA interference against GATA6 expression, there were significantly more apoptotic cells compared with the control group (P＜0.05), and cell proliferation was obviously inhibited (P＜0.05). Conclusion GATA6 is abnormally highly expressed in insulinoma, and closely related with the cell proliferation and apoptosis, indicating that it may play an important role in insulinoma pathogenesis.