HSPA9 and neoplasm: UBXN2A promotes the carboxy-terminal ubiquitination of mot-2 that is dependent on the HSP70-interacting protein (CHIP). UBXN2A increases the proteasomal degradation of mot-2. Subcellular compartmentalization experiments show that UBXN2A can reduce the expression levels of mot-2 and its chaperone HSP60. The existence of a multi-protein complex of UBXN2A, CHIP, and mot-2 indicates that UBXN2A and CHIP have synergistic tumor suppressor activity in tumors enriched with mot-2.