HDAC6 and syndromic intellectual disability: Tac, a novel benzamide‐based HDACi that completely inhibits class I HDACs and to a smaller extent HDAC6 (Beckers et al., 2007), was shown to improve cognition in an intellectual disability syndrome mouse model (Cooper et al., 2020), to increase neuronal plasticity after traumatic brain injury (Sada et al., 2020), to promote functional recovery following spinal cord injury (Zhang et al., 2018) and to reduce antipsychotic haloperidol‐induced motor side effects and memory impairment in aged mice (McClarty et al., 2021).