The B-ALL–mediated MSC to CAF transition is accompanied by a robust IFN pathway response. (A) Two volcano plots showing differentially regulated genes from HS27a cells cultured in SD-1 conditioned medium compared with RPMI, and HS27a cells cultured in SEM conditioned medium compared with RPMI, as indicated. (B) Dot plots of the top 15 pathways enriched in HS27a cells cultured in SD-1 conditioned medium compared with RPMI, and HS27a cells cultured in SEM conditioned medium compared with RPMI, as indicated. Dot size is proportional to log₁₀(size of pathway set), and color is proportional to adjusted P value. All P values were highly significant, as indicated. (C) Bar chart showing fold upregulation (X axis) of IFN pathway genes indicated on the Y axis. (D) Validation of RNAseq IFN response finding in 2 primary, HD1 and HD9 MSCs cocultured with 4 different primary ALL cell specimens (X axes). The Y axis indicates fold change in gene expression.