CD27⁻IgA⁺ memory B cells resemble colon lamina propria IgA⁺ B cells. (A) Replication history in naive mature, IgA⁺ memory B-cell subsets and CD19⁺IgA2⁺ B cells isolated from human colon lamina propria as measured with the KREC assay. Bars represent mean values with SEM. Statistical significance was calculated with the Mann-Whitney test. (B) Igκ and Igλ isotype distribution of naive mature and IgA⁺ memory B cell subsets as determined with flow cytometric analysis. (C) Frequency of mutated nucleotides in rearranged IGLV gene segments. All individual data points are showed as gray dots, with red lines indicating the median value. Statistical significance was calculated with the Mann-Whitney test. **P < .01.