Cbx6, a subunit of Polycomb Repressive Complex 1 (PRC1), mediates epigenetic gene repression. It is involved in various biological processes and associated with multiple pathways [2,5,6,7]. In mouse embryonic stem cells, it is essential for cell identity, with its depletion destabilizing the pluripotency network and triggering differentiation [6].

In cancer, Cbx6 shows diverse roles. In hepatocellular carcinoma (HCC), its up-regulation promotes cell proliferation, migration, invasion, and EMT process via Snail/Zeb1-mediated mechanism, and is associated with poor prognosis [1,4]. In breast cancer, it is negatively regulated by EZH2 and acts as a tumor suppressor, inhibiting cell proliferation, colony formation, migration, and invasion [2]. In mesothelioma, proteasomal degradation of Cbx6 promotes MMP-2 expression and cell invasion [5]. In bladder cancer, it may contribute to a poor prognosis by inhibiting M1 macrophage polarization and promoting Treg recruitment [3].

In conclusion, Cbx6 is crucial for maintaining embryonic stem cell identity. In cancer, its role varies among different cancer types, either promoting or suppressing tumor development. The study of Cbx6 in these disease models helps to understand the underlying molecular mechanisms and provides potential therapeutic targets for related diseases.