Hydrolase that can remove conjugated ubiquitin from proteins in vitro and may therefore play an important regulatory role at the level of protein turnover by preventing degradation. Mediates deubiquitination of 'Lys-11'-,'Lys-48'- and 'Lys-63'-linked polyubiquitin chains, with a preference for 'Lys-63'-linked polyubiquitin chains. {ECO:0000269|PubMed:12704427, ECO:0000269|PubMed:18954305, ECO:0000269|PubMed:23827681}. This is the function of ENSG00000089723 (OTUB2, OTU deubiquitinase, ubiquitin aldehyde binding 2).