Chromosome 18 loss was found in 4/6 (67%) NOM, 2/5 (40%) PON‐T−, 1/5 (20%) PON‐T+, 5/10 (50%) ileal NET, and 1/10 (10%) rectal NET (supplementary material, Figure S1B). Here, PON1 is linked to rectum neuroendocrine neoplasm.