CD79A and rheumatoid arthritis: The effect of ritlecitinib on CeD serology (tTG-IgA, DGP-IgA/IgG) levels was retrospectively evaluated in participants from three phase 2 and one phase 3 ritlecitinib clinical trials including participants with active AA, rheumatoid arthritis (RA) and vitiligo, whose serum samples at baseline and post-treatment were available.