MKI67 and neoplasm: One difference between the REAL-LU study population and patients in the NETTER-1 study was that our real-world population included a high proportion of patients (71%) with grade 2 (Ki-67: 3–20%) GEP-NETs whereas the majority of the NETTER-1 trial population (66%) had grade 1 NETs [13]. With regard to the tumor grade profile, our study cohort appears to be closer closer to that of the NETTER-2 study population, which included patients with G2 or G3 advanced GEP-NETs (i.e. Ki-67 ≥ 10% and ≤ 55%).