RRM2 and neoplasm: Finally, in our ACC cohort, patients with high RRM2 expression levels at the tumor level showed a strong tendency towards poorer overall survival compared to the others (median survival 36 vs. 124 months, p = 0.05, HR 5.11, 95%CI 1.26–20.82; Figure 4F), while no such effect was detectable for RRM1 (Figure 4E; p = 0.177).