Chin-Jung Wang,a An-Shine Chao,a Shuenn-Dyh Chang,a Ting-Chang Chang,a Chyong-Huey Lai,a and Hsin-Shih Wanga,l

Ovarian cancers are frequently not diagnosed until ad-vanced stages, resulting in a high case fatality rate. Be-cause of this, more tumor markers, in addition to CA125, for detecting and monitoring ovarian cancer are needed. During a systematic search for potential biomarkers of ovarian cancer, we compared the protein profiles be-tween tumor interstitial fluid and normal interstitial fluid of ovaries, rationalizing that abnormal levels of proteins in tumor interstitial fluid may be detected in peripheral blood and thus serve as easily accessible tumor markers. Here, we show that stress-induced phosphoprotein 1 (STIP1) was secreted by ovarian cancer tissues into the periph-eral blood of patients, resulting in a significant increase of serum levels of STIP1 in cancer patients compared with those in age-matched normal controls. Our result