Cadherin-1 also known as CAM 120/80 or epithelial cadherin (E-cadherin) or uvomorulin is a protein that in humans is encoded by the CDH1 gene. CDH1 has also been designated as CD324 (cluster of differentiation 324). It is a tumor suppressor gene. ---- [[Clinically non-functioning pituitary neuroendocrine tumor]]s (NF-[[PitNET]]s) present a varying degree of [[aggressiveness]], and reliable [[prognostic marker]]s are lacking. Øystese et al. aimed to characterise the distribution of [[E-cadherin]] and [[N-cadherin]] in corticotroph, [[PIT1]] and [[null-cell]] NF-[[PitNET]]s, and link it to the course of the tumours. The distribution of [[E-cadherin]] and N-cadherin was investigated by immunohistochemistry in a retrospective cohort of 30 tumours of the less common NF-PitNETs (corticotroph (N = 18), PIT1 (N = 8) and null-cell PitNETs (N = 4)). Immunoreactive scores (IRS) were compared to previously presented cohorts of gonadotroph NF-PitNETs (N = 105) and corticotroph functioning PitNETs (N = 17). They found a low IRS for the extracellular domain of E-cadherin (median 0 (IQR 0-0, N = 135)), a medium to high IRS for the intracellular domain of E-cadherin (median 6 (IQR 4-9)) and a high IRS for N-cadherin (median 12 (IQR 10.5-12)) throughout the cohort of NF-PitNETs. The corticotroph NF-PitNETs presented a higher IRS for both the extra- and intracellular domain of E-cadherin (median 0 (IQR 0-1) and median 9 (IQR 6-12), respectively) than the gonadotroph NF-PitNETs (p < 0.001 for both comparisons). The presence of nuclear E-cadherin was associated with weaker staining for the intracellular domain of E-cadherin (median 4 (IQR 0.5-6) and median 9 (IQR 9-12), for tumours with and without nuclear E-cadherin, respectively), and with a lower rate of re-intervention (p = 0.03). Considering the results and the benign course of NF-PitNETs, they suggest that a high N-cadherin and downregulation of membranous E-cadherin are not associated with a more aggressive tumour behaviour in these subgroups of NF-PitNETs ((Øystese KAB, Casar-Borota O, Berg-Johnsen J, Berg JP, Bollerslev J. Distribution of E- and N-cadherin in subgroups of non-functioning pituitary neuroendocrine tumours. Endocrine. 2022 Jun 8. doi: 10.1007/s12020-022-03051-6. Epub ahead of print. PMID: 35674926.)).