VRK3 is a serine/threonine kinase that functions as a multifaceted regulator of cell cycle progression, neuronal survival, and immune homeostasis. Mechanistically, VRK3 phosphorylates the nuclear envelope protein BAF to regulate nuclear envelope dynamics during mitosis 1. Under normal conditions, VRK3 acts as a negative regulator of ERK signaling by enhancing VHR phosphatase activity in the nucleus, preventing prolonged ERK activation 2. During oxidative stress, CDK5-mediated phosphorylation of VRK3 amplifies this neuroprotective pathway, while VRK3 also promotes nuclear localization of HSP70 to further suppress excessive ERK activation 3. Notably, VRK3 protects cells from oxidative stress-induced apoptosis; conversely, RNF144a-mediated VRK3 degradation sensitizes cells to ERK-dependent cell death 4. Disease relevance is substantial: VRK3 deletion causes autism-like behaviors with reduced dendritic spine density, reversible by TrkB stimulation 5. Genetic variants in VRK3 show causal associations with Alzheimer's disease pathogenesis 62 and systemic lupus erythematosus across immune cell types 7. Additionally, VRK3 upregulation correlates with poor prognosis in head and neck squamous cell carcinoma 8. These findings position VRK3 as a therapeutic target for neurodegenerative diseases and autoimmune conditions.