Figure 4. Proximal and Distal Fibroblast populations identified in single cell transcriptome data of PDAC.

(A) Average expression of spatially defined tumor-proximal or tumor-distant stromal genes within cell types defined by scRNA-seq (n=3). (B) UMAP embedding of scRNA-Seq data from fibroblasts overlaid with (left to right) expression of the canonical fibroblast marker genes DCN, LUM and THY1; COL1A2 found in CAFs; gene set variation analysis (GSVA) signature score for tumor-proximal (DKK3, PDPN, PTENSTAT2, B2 and STAT1) or tumor-distal (STAT3, IL6, C3, VSIR, CD34, CSF1R, THY1, SFRP2) associated stromal genes; Clustering based on unsupervised Louvain assignment. n=229 Fibroblast cells.(C) Average cluster-wise expression profile of selected proximal and distant stroma associated genes as identified by spatial profiling. (D) Differential expression analysis between sc-proximal and sc-distant fibroblast cells. Colored points indicate differentially expressed genes (BH adjusted p<0.05 & absolute log₂FC >0.5). (E) Violin plots depicting cluster-wise expression distribution of canonical myCAF and iCAF marker genes. (F) GSVA score profiles identified as differentially enriched (BH adjusted p<0.001) in sc-distant vs sc-proximal cells. (G) Average within-cluster expression profile of Complement, Retinoic acid metabolism and Wnt ligand biogenesis gene sets. Grey = no detectable expression.