Fig 1: B cell clusters in NPC.a t-SNE plot showing 10 clusters of 17,353 B cells (indicated by colors). b t-SNE plot, color coding for the expression of the marker genes (gray to red) for the indicated cell subtypes. c Potential developmental trajectory of B cells (n = 17,353) inferred by analysis with Monocle 2. Arrows show the increasing directions of certain B cell properties annotated with the signatures shown in d. d Traceplots of (left) B cell proliferation signature along proliferation component and (right) antigen secretion signature along antigen secretion component for the B cells. Cells are projected along the component, with the blue line indicating the moving average of the expression of signatures (a sliding window of length equal to 5% of the total number of B cells was used), and the shaded area displaying SEM. Signatures used are presented in Supplementary information, Table S9. e Comparison of pathway activities (calculated based on GSVA) among different B cell subtypes. The scores of pathways are normalized. f Heatmap showing the activity of TFs in each B cell subtypes. The TF activity is scored using AUCell. g t-SNE plots of B cells color coded according to the expression of BCL6 and ATF4 or the AUC of the estimated regulon activity of these transcription factors, which corresponded to the degree of expression regulation of their target genes. h Left, FACS analysis of BCL6 expression in GC and other B cells from tumor tissues. The results represent five independent experiments (n = 6 donors). Right, association between GC B cells and BCL6+ B cells (n = 6) from tumor tissues. **P < 0.01 (paired Student’s t-test). Error bars, SEM. i Left, FACS analysis of ATF4 expression in plasma cells and non-plasma B cells from tumor tissues. The results represent four independent experiments (n = 5 donors). Right, association between plasma cells and ATF4+ B cells (n = 5) from tumor tissues. *P < 0.05 (paired Student’s t-test). Error bars, SEM.