WFDC2 and neoplasm: Similar to the biomarker HE4 [20], peptides for Urokinase plasminogen activator surface receptor (UPAR) and folate-receptor-alpha (FOLR-a) [21, 22] were found in the swab and Pap test fluid, but not in the tumor tissue (although only a single peptide for FOLR-a was found in the Pap test fluid).