Botling J, Lamarca A, Bajic D, et al. - In this retrospective cohort study, researchers described changes in Pancreatic Neuroendocrine Tumors (PanNETs) differentiation and proliferation over time, and correlated findings to overall survival. A total of 475 PanNET patients were screened during treatment at Uppsala University Hospital, Sweden. The researchers included 46 patients with 106 tumor samples in their analyses. In a majority of PanNETs, a longitudinal increase in Ki-67 index and an increase in tumor grade were noted. Further study was proposed as essential biomarkers in PanNET to increase the Ki-67 index and high-grade progression.