USP14 and aceruloplasminemia: For example, USP14 deletion, characterized by cerebellar ataxia, was found to result in increased GABAA receptor levels in Purkinje cells [158], and considering GABAARs mediate a majority of the fast synaptic inhibition in the mammalian brain, one might reason that USP14 regulation of GABAARs is central to maintaining output neurons of the cerebellar cortex and the regulation of motor coordination in Purkinje cells.