QUIPS assessments highlighted greatest concerns for selective study participation and heterogeneous Ki-67 cutoffs, while outcome measurement, confounder adjustment, and statistical reporting were generally lower risk.<h4>Conclusions</h4>Higher Ki-67 LI is associated with an increased hazard of death in patients with glioblastoma, with effects persisting after multivariable adjustment and limited between-study heterogeneity. The gene discussed is MKI67; the disease is glioblastoma.