HDAC9 and androgen insensitivity syndrome: Findings from the current SOLVE study, a phase two randomised placebo-controlled trial testing the ability for sodium valproate to improve 90 day outcomes for patients experiencing AIS will provide valuable insight to the potential utility of pan HDAC inhibition in this patient population (https://clinicaltrials.gov/study/NCT06020898 accessed August 2025).23 It is important to note, however, that sodium valproate does not target HDAC6 and this trial will therefore not directly assess whether HDAC6 inhibition benefit patients experiencing AIS.