VQ myeloma cells display unique transcriptional signatures from normal plasma cells. CD138⁺B220⁻ cells were sorted from age-matched control BM (Con-BM) and VQ-D2 BM and LN. scRNA-Seq analysis was performed as described in “Methods.” (A) tSNE plot depicting 749 single plasma cells derived from control and VQ-D2 mice. Each cluster is represented by a specific color and number. The top 20 genes expressed in each cluster are presented in the heatmap. (B) Samples are color-coded and projected on the tSNE plot (blue, Con-BM; red, VQ-BM; green, VQ-LN). (C) Cell-cycle phases are color-coded and projected on the tSNE plot (red, G₁; green, G₂/M; blue, S). (D) GSEA was performed between VQ-BM and Con-BM plasma cells. Adjusted P value (P.adj) and normalized enrichment score (NES) are shown on each plot. (E) Signature module scores were calculated for each cell based on the expression levels of genes associated with high-risk MM and the average expression profile of each cell. P value was determined using the Welch t test between VQ (BM + LN) and Con-BM. ES, enrichment score.