AKT1 and brain injury: In line with reports suggesting that the PI3K/AKT pathway can positively regulate AQP4 expression in myocardial ischemia, brain trauma, and cerebral ischemic diseases (Kapoor et al., 2013; Chien et al., 2015; Chu et al., 2017; Zhao et al., 2017; Song et al., 2018), our study found that both PI3K, AKT, and AQP4 levels increased, indicating that PI3K/AKT activation can also positively regulate the expression of AQP4 after ICH, which affects brain edema.