KRT18 and cancer: The epithelial OC origin of the PDC2 and PDC3 samples was confirmed by the expression of OC-specific markers PAX8 and CD24, epithelial makers MKI67, EPCAM, KRT8 and KRT18 and cancer stem cell markers such as CD44 and ROR1 (Fig. 2b and Supplementary Fig. 2c).