The gene SNCG (synuclein γ) serves as a marker for adverse and aggressive disease in breast cancer. The mRNA is found to be overexpressed in uterine serous carcinoma compared to uterine endometrioid adenocarcinoma. It may serve as a predicting marker for aggressive tumors and severe outcome in patients with endometrial cancer. It is also found to be expressed in several malignant ovarian tumors. It may participate in cell proliferation.