Compared to GF mice, fecal IgA and the number of IgA-producing plasma cells (B220−IgA+) in the SI-LP from GF-AF mice were decreased; by contrast, there was no significant difference between GF and GF-AF mice in the number of IgA plasma cells in the LI-LP (Figures 1A,B). Here, CD79A is linked to atrial fibrillation.