PIAS4 and schizophrenia: It has been described that TRIM32 ubiquitinates, among other substrates, dysbindin (a protein involved in endosomal-lysosomal trafficking and the genetic aetiology of schizophrenia) [33], and PIASy [Protein Inhibitor of Activated STAT (Signal Transducer and Activator of Transcription) isoform y, an E3-SUMO ligase] [34].