Psmb6, the proteasome 20S subunit beta 6, is a member of the proteasome family. It encodes a subunit that performs caspase-like proteasome activity and is involved in multiple cellular processes such as antigen presentation by MHC class I molecular [4]. The ubiquitin-proteasome pathway, in which Psmb6 is a part, is crucial for protein degradation and cellular homeostasis.

In multiple myeloma, knockdown of Psmb6 by shRNA increased sensitivity to bortezomib in both resistant and sensitive cell lines, suggesting it's a novel target for overcoming bortezomib-resistance [1]. In lung adenocarcinoma, elevated Psmb6 expression was correlated with tumor growth and poor prognosis. Knockdown of Psmb6 in vitro inhibited cell proliferation, migration, invasion, and promoted apoptosis [2]. In zebrafish, deficiency of psmb6 led to early embryonic death due to proteasome inactivity and consequent neuronal apoptosis [3].

In summary, Psmb6 plays a vital role in maintaining normal cellular functions including proteasome-mediated protein degradation. Its dysregulation is associated with diseases like multiple myeloma and lung adenocarcinoma. Studies using gene-knockdown or knockout models in different organisms have provided insights into its role in disease development, offering potential therapeutic targets for these diseases.