The pooled results of the 12 datasets from the 11 studies with a random-effect model showed that higher tumor CD44 expression significantly predicted the poor OS in patients with glioma during follow-up (HR: 1.42, 95% CI: 1.02–1.97, P=0.04; Figure 2) with significant heterogeneity (P for Cochrane’s Q test = 0.02, I2 = 51%). The gene discussed is CD44; the disease is glioma.