2012). AQP4, an important component of the brain glymphatic system, is essential for improving CSF flow and elimination of waste products within the cerebral parenchyma (Benveniste et al. 2019). AQP4 expression is significantly reduced in T2DM, causing impaired glymphatic system performance (Zhang et al. 2016). Here, AQP4 is linked to type 2 diabetes mellitus.