HP and rheumatoid arthritis: Of note, MRM has enabled successful quantification of differential expression of IgG subclass glycosylation (160), haptoglobin glycoforms (161, 162), and core fucosylation (163) in liver disease, profile changes in galactosylation and sialylation in rheumatoid arthritis (RA) patients (164) quantify glycoproteins in esophagus disease (165), reveal alterations in murine immunoglobulin glycoforms (166), characterizing the function and importance of UDP-GlcNAc transporter (167), and quantitation of Golgi-resident glycosylation enzymes from cultured human cells (168).