Found 1 pathways with zero (PubMed) references
* [http://classic.wikipathways.org/instance/WP2485_r117161](http://classic.wikipathways.org/instance/WP2485_r117161) 'NAD biosynthesis II (from tryptophan)' in Homo sapiens has zero references;
More details at https://www.wikipathways.org/WikiPathwaysCurator/ReferencesTests/atLeastOneReference