The exosome is a multisubunit complex composed of several highly conserved subunits, some of which are 3’ to 5’ exoribonucleases. The complex is involved in a variety of cellular processes and is responsible for degrading unstable mRNAs that contain AU-rich (ARE) elements in their untranslated 3’ region. EXOSC5 (Exosome component 5), also known as Exosome complex exonuclease RRP46 and CML28 (Chronic myelogenous leukemia tumor antigen 28), is one of at least eleven components of the exosome complex and is required for processing of 7S pre-RNA to mature 5.8S rRNA. Located in the nucleus, EXOSC5 interacts with both EXOSC1 and EXOSC7. EXOSC5 is exclusively expressed in normal testis, though is found to be highly expressed in many hematopoietic and epithelial tumor cell lines, suggesting that it may be an appropriate target for antigen-specific immunotherapy.