Additionally, since the expression level of NEU3, a plasma membrane-associated sialidase, is remarkably increased in various human cancers such as colon, renal, prostate and ovarian cancers [1], [2], [3], detection of membrane sialidase activities in viable cancer tissue will also be useful for cancer diagnosis and real-time monitoring of cancer during a surgical operation. The gene discussed is NEU3; the disease is ovarian cancer.