CD73 is an enzyme found on cell surfaces that can dampen the immune system responses. Already known to be involved in tumour progression and metastasis, a collaboration of RRCancer researchers (including the team of Dr. J. Stagg and 3 other network members) found that its levels can be used as an indicator of prognosis in high-grade serous ovarian cancer. High levels of CD73 were found to indicate poor prognoses in patients, because it allows tumour cells to bypass the immune system and spread. However, CD73 is also a promising target for immunotherapy. Patients with elevated CD73 may one day be able to be treated to lower their CD73 levels and improve their prognoses.