Multiple recent studies highlight the Ki-67 proliferation index as a key predictor of PRRT efficacy, showing that patients with lower Ki-67 (e.g. ≤~50%) achieve significantly longer median PFS and OS after PRRT than those with higher proliferative rates​ 44 Likewise, imaging-based measures of SSR expression such as the KS correlate strongly with treatment response, as higher uptake scores have been associated with greater tumor remission rates and extended PFS compared to lower scores​ 45. The gene discussed is MKI67; the disease is neoplasm.