HDAC9 and nervous system disorder: More importantly, targeting HDACs by pan and selective HDAC inhibitors (HDACis) has emerged as a highly promising therapeutic strategy for multiple neurological disorders, such as neurodegenerative diseases (Chuang et al., 2009; Ziemka-Nalecz et al., 2018; Shukla and Tekwani, 2020), psychiatric disorders (Abel and Zukin, 2008), and acute brain injury (Yang et al., 2021).