In a multicenter retrospective cohort of 149 patients with G3 GEP-NENs treated with PRRT, the median PFS was 19 months in G3 NET, 11 months for NEC with Ki-67 ≤ 55%, and 4 months for NEC with Ki-67 > 55% [237, 238]. The gene discussed is MKI67; the disease is neuroendocrine carcinoma.