These data align with previously published demonstrations of NKCC1‐mediated increase in brain fluid content and ventriculomegaly in rat models of subarachnoid hemorrhage, intraventricular hemorrhage, and traumatic brain injury,[33, 70, 71] and the associated improved outcome upon NKCC1 inhibition.[40]. This evidence concerns the gene SLC12A2 and subarachnoid hemorrhage.