RRM2 and central nervous system cancer: The median RRM2 positivity (% of RRM2+ cells) in our cohort was 1% and Cox regression analysis showed that glioma patients negative for RRM2 (RRM2 negat., median survival not reached) had longer survival times than RRM2 positive patients (RRM2 positive; median survival=222 days, Log-rank P=0.00; Fig. 6f).