BDNF and ovarian carcinoma: Current studies have demonstrated that sevoflurane inactivates CREB, a key epigenetic regulator of BDNF, by suppressing SIRT1, PKA, and ovarian cancer G-protein-coupled receptor 1 (GPR68), thereby reducing hippocampal BDNF expression and mediating cognitive dysfunction and learning/memory impairments in experimental animals (Tang X. et al., 2020; Zhao J. et al., 2021; Zhao et al., 2022; Figure 3, Loop 4).