GP2 and systemic lupus erythematosus: Conversely, increasing A2 glycan (GP2) and decreasing FA2G2 glycan (GP14) are consistent with the changing of certain IgG N-GPs which have been observed in association studies on chronic diseases (Supplementary Table 8), such as dyslipidemia (DL) (67), SLE (62), RA (68), and chronic kidney disease (CKD) (69).