The present invention relates to a method of diagnosing whether a subject has, or is at risk for developing, pancreatic cancer, comprising measuring the level of at least one miR-155 gene product in a test sample from said subject, wherein a decrease in the level of the miR-155 gene product in the test sample, relative to the level of a corresponding miR-155 gene product in a control sample, is indicative of the subject either having, or being at risk for developing, pancreatic cancer. The pancreatic cancer may comprise a pancreatic endocrine tumor (PET).
