WFDC2 and ovarian cancer: While HE4 protein is overexpressed in over 90% of ovarian cancer tumors, it has also been detected in normal fallopian tubes, endometrium and cervix by immunohistochemistry [36], although we did not observe peptides to HE4 in the “Normal Pap test Core Proteome” defined in our previous analysis of normal Pap test fluid [8].