MKI67 and pancreatic neuroendocrine tumor: An association between the ADC value and the Ki-67 index has been shown for various kinds of tumours2,14–18,34–38, including lung cancer.3,6 Wang et al., in their study on DWI in pancreatic endocrine tumours, reported a correlation coefficient of −0.702, while Onishi et al. reported a correlation coefficient of −0.825 for mucinous breast carcinoma.15