Retrospective research showed that two chemokine receptors, CXCR4 and CXCR7, can be used as molecular prognosis factors. People who express low levels of both chemokine receptors have the highest odds of long-term survival with >90% survival at five years post-diagnosis versus <30% survival at five years for patients with very high expression levels of both receptors. A recent study also suggested a role for SOX2 as an independent prognostic biomarker that can be used to identify patients at high risk for tumor relapse.