Given that FAP is predominantly expressed in CAFs (23), human primary CAFs from several tumor types were isolated and their molecular characterization was identified as being negative for leukocyte (CD45), endothelial (CD31), epithelial (CD326), positive for hFAP, α-SMA and with an elongated spindle-like morphology (Supplementary Figure 2A). The gene discussed is ACTA1; the disease is neoplasm.