ARID1A alterations were significantly more common in WHO grade 3 meningiomas (n = 26/176, 14.8%) than in WHO grade 2 (n = 18/441, 4.1%, p = 0.0001) and WHO grade 1 meningiomas (n = 1/220, 0.4%, p = 0.0001). Here, ARID1A is linked to meningioma.