Specifically, our primary human iCCA cell cultures (i.e. mucinous and mixed iCCAs), after 20–40 passages, were particularly enriched in cells expressing cancer stem cell markers and EMT markers but were negative for markers of contaminant cells including hematopoietic cells (CD45), tumor-associated macrophages (CD163), activated hepatic stellate cells (GFAP), endothelial cells (CD31), fibroblast-activation protein (FAP), and stromal-derived factor (SDF1) [3, 19]. The gene discussed is FAP; the disease is cancer.