Since astrocytes following brain injury or ischemia become reactive, aromatase activity by these cells in particular may mediate neuronal recovery from injury (Garcia-Segura et al., 1999; Melcangi et al., 2016) Indeed, evidence supports the hypothesis that the protective effects of astrocytes is due to E2 availability (i.e., dependent upon aromatase activity), although whether sex differences exist remains unclear (Garcia-Segura et al., 1999). Here, CYP19A1 is linked to ischemia.