PHKB and cyst: Among 642 differentially expressed glycoproteins, four N-glycoproteins with specific glycosites and glycoforms were identified as potential cyst fluid biomarkers that could accurately distinguish malignant PCNs: N-glycosylated ATP6V0A1 (Asn-273, H5N4F0S1), ATP6V0A4 (Asn-367, H6N4F0S0), CEACAM5 (Asn-197, H5N4F0S0) and PHKB (Asn-935, H5N2F0S0, H4N4F0S0 and H5N4F0S0) (Fig. 4a, b).