P2/CD23⁺and P2/CD23^–cells show a differential response to IL-4. (A) Boxplot of ATAC-seq read densities for regions associated with the 200 genes with the highest scores (top, 384 regions) and lowest scores (bottom, 426 regions) on the RNA-seq PC2 axis during NBC differentiation. Note that regions associated with the genes from the positive end of the rPC2 axis are open in NBCs but closed during differentiation, whereas regions associated with genes from the negative end of the rPC2 axis are more open in P2/CD23⁺ cells only (in agreement with the position of this population at the lower end of the rPC2 axis). (B) Ranking of genes according to their rPC2 weights; known IL-4/STAT6 response genes are indicated in orange. (C) GSEA of genes ranked according to their rPC2 weights for 2 IL-4 signatures (B cells in the presence or absence of IL-4). (D) Top panel: positions of genes from Ruiz-Lafuente’s IL-4 signature associated with P2/CD23⁺ and P2/CD23^– cells (orange dots and left cyan diamonds and right purple diamonds, respectively) on the RNA-seq PCA distribution. Middle panels: boxplots of RNA-seq data for these genes in NBCs and the different in vitro cell populations. Bottom panels: ATAC-seq densities of regions associated with genes from the IL-4 pathway and associated with P2/CD23⁺ (left) or P2/CD23^– (right); the observed changes in chromatin accessibility are suggestive of a differential response to IL-4. NS, not significant.