Naïve B subsets analysis in IgAN patients compared with HSs and controls. PBMCs were isolated from the peripheral blood of 36 IgAN patients, 13 HSs and 22 patients with non-IgA glomerulonephritis (controls) and analysed by flow cytometry. The gating strategy used to identify lymphocytes (A, left panel), CD19⁺ B cells (A, right panel) and B-cell subsets (A, lower panel) is shown for one representative IgAN patient. For each B-cell subset we then analysed the expression of IgA and/or CCR9 and integrin β7 as shown in the panels.