A novel marker, dipeptidase 1 (DPEP1), was found to be of clinical use in distinguishing primary mucinous ovarian cancer from ovarian metastasis of GI cancers [68]; if combined with other IHC markers (CDX2 and CK7), together with a single clinical factor (tumor size), DPEP1 can provide an accuracy of 93% [68]. This evidence concerns the gene DPEP1 and mucinous ovarian cancer.