OPRM1 and bile duct papillary neoplasm: At the mRNA level, two of the designated three ChAT neuronal superclusters and the single Tac1 supercluster demonstrate significant expression of OPRM1 (mean expression levels including zero values = 0.33, 6.8 and 4.1 in ChAT Superclusters 0632, 0634, 0635, respectively and 8.7 in the Tac1 Supercluster 0633; Figure1d) At the protein level, and as previously reported23, we confirm that mOR expression is notable in the mHb, the fasciculus retroflexus axonal tracts and particularly prevalent in the IPN (Figure 1e).