Rosacea is a common inflammatory facial skin disorder. The pathogenesis is poorly understood, although increased matrix metalloproteinase (MMP) activity may play an important role. Glioma accounts for 80% of primary central nervous system malignant tumors, and glioma also shows upregulation of MMP. In this nationwide cohort study, Egeberg et al demonstrate that rosacea was associated with a significantly increased risk for glioma. Increased focus on neurologic symptoms such as headache, memory loss, seizures, visual changes, or personality changes in patients with rosacea may be warranted.