FAP and neoplasm: In five of the six possible cross-species comparisons, a significant Pearson correlation coefficient (p < 0.05) was observed between the human epithelial and mouse CAF markers (Table 1; Figure S6A–S6F), particularly between EPCAM and Fap (r = 0.37, p = 7.90E–4; Figure S6A) indicating the positive relationship between tumor epithelial cell type and fibroblast activation exists in the PDX panel.