There are multiple definitions:

1. NEderlands Normalisatie-instituut(Dutch)

   • ANSI, CGS, FPS, KEMA, SI
   • Organizations (scientific), Medical technology (assessment)
   • https://www.nen.nl/Home.htm

2. neuroendocrine neoplasm(English)

   • rare neoplasm with heterogeneous clinical behavior. Alteration in human microbiota was reported in association with carcinogenesis in different solid tumors
   • I-NEN, FIGO, GCIG, NCDB, NEC, NECC, NSE
   • Cell biology, Endocrinology, Neurology, Oncology
   • https://doi.org…0/cells11040692