HDAC9 and androgen insensitivity syndrome: For example, genome-wide association studies have highlighted that a single nucleotide polymorphism (RS11984041) in the HDAC9 gene is associated with increased risk of large artery AIS.16,17In vitro and in vivo data have also highlighted that the expression and activity of multiple HDACs is increased in AIS-affected brain tissues.18, –20 Independent studies using in vitro and in vivo models have also reported that AIS-severity is significantly reduced when administering pharmacological HDAC inhibitors, compared to controls (reviewed by Majdi et al.21).