The content of the Biolookup Service's underlying database is broken into several pieces:
        The names dataframe has three columns: prefixes, identifiers, and names.
        
        
    
        The species dataframe has three columns: prefixes, identifiers, and species denoted with NCBI taxonomy identifiers.
        
        
    
        The definitions dataframe has three columns: prefixes, identifiers, and text descriptions.
        
        
    
        The alternative identifiers dataframe has three columns: prefixes, identifiers, and alternative identifiers.
        
        
    
        The synonyms dataframe has three columns: prefixes, identifiers, and synonyms.
        
        
    
        The cross-references dataframe has five columns: prefixes, identifiers, xref prefix, xref identifier, and
        source.
        
        
    
        The cross-references dataframe has six columns: prefixes, identifiers, relation prefix, relation identifier,
        target prefix, and target identifier.