Clonally related and unrelated sequences over time. The stacked bar graph indicates the numbers of immunoglobulin heavy-chain (IgH) sequences with identifiable rearrangements that were obtained by single-cell sequencing in all six subjects with Sjögren’s syndrome (SjS). White bars indicate unrelated IgH rearrangements. Red bars indicate IgH rearrangements that are present in at least two independent sequences and are therefore deemed to be clonally related. The numbers of unique and clonally related sequences obtained for each subject at each time point are given in Additional file 2: Table S1. BL, baseline.