HMOX1 and subarachnoid hemorrhage: Increased heme oxygenase-1 immunostaining was induced at the place of the cerebral cisterns suggesting that subarachnoid hemoglobin concentration plays an important role in regulating heme oxygenase-1 levels (Matz et al., 1996) and that it is the major enzyme responsible for clearing blood from the subarachnoid space following subarachnoid hemorrhage (Schallner et al., 2015).