While "J2" and "RAR" appear in several contexts, your request most likely refers to the isoform, which is a critical tumor suppressor gene in cancer research.
One of the most common reasons RARβ2 stops working is epigenetic silencing through a process called DNA methylation. In many malignancies, such as lung and head and neck cancers, the promoter region of the RARβ2 gene—essentially its "on switch"—becomes chemically modified by methyl groups. This physical blockage prevents the cell's machinery from reading the gene. Furthermore, enzymes known as histone deacetylases (HDACs) help lock the DNA into a tightly coiled, inactive state, further ensuring that the gene remains silent. J2 rar
dtic.mil/sti/tr/pdf/ADA386879.pdf">RARβ2 methylation process, or should I expand on its role in a specific type of cancer like lung cancer ? While "J2" and "RAR" appear in several contexts,