Wednesday, November 20, 2024 Biomarkers to Inform Prognosis and Treatment for Unresectable or Metastatic GEP-NENsLoree JM, Chan D, Lim J, Stuart H, Fidelman N, Koea J, Posavad J, Cummins M, Doucette S, Myrehaug S, Naraev B, Bailey DL, Bellizzi A, Laidley D, Boyle V, Goodwin R, del Rivero J, Michael M, Pasieka J, Singh S. Biomarkers to Inform Prognosis and Treatment for Unresectable or Metastatic GEP-NENs (ONLINE). JAMA Oncology 2024. https://doi.org/10.1001/jamaoncol.2024.4330 Objective To create an accessible guidance document to educate clinicians and patients on biomarkers informing prognosis and treatment in unresectable or metastatic GEP-NENs.Conclusions and Relevance The study results suggest that select factors have sufficient evidence to inform care in GEP-NENs, but the evidence for most biomarkers is weak. This article may help guide management and identify gaps for future research to advance personalized medicine and improve outcomes for patients with GEP-NENs.