Updated publication reference for PubMed record(s): 29872131. At times, it can be difficult to discern if a lack of overlap in reported interactions for a protein-of-interest reflects differences in methodology or biology. A case in point is the prion protein (PrP) which is best known for its central role in prion disorders. Despite having over two dozen interactors reported, there is little consensus regarding their importance for understanding the biology of PrP. In such instances, systematic analyses of protein-protein networks across diverse paradigms can provide valuable insights. Here, we interrogated the PrP interactome in four distinct mouse cell lines. Analyses made use of identical affinity capture reagents and sample processing workflows. To enable the discrimination of specific from non-specific binders, negative controls were generated from PrP knockout lines of the respective cell models, and the relative levels of peptides were quantified with the help of isobaric labels. The study uncovered 26 proteins, which reside in proximity to PrP. All of these proteins are predicted to have access to the outer face of the plasma membrane, and approximately half of them were not reported to interact with PrP before. Strikingly, although several proteins exhibited profound co-enrichment with PrP in a given model, except for Ncam1, no protein was highly enriched in all four PrP-specific interactome datasets.