C3AR1 and subarachnoid hemorrhage: Similarly, Gao17 used these similar approaches to find that immune responses may be associated with both epilepsy and subarachnoid hemorrhage pathogenesis and that Matrix metalloproteinase-9 (MMP9) and Complement C3a Receptor 1 (C3aR1) may be potential diagnostic markers for subarachnoid hemorrhage complicated by epilepsy.