Furthermore, IL-6’s impact on the integrity of the blood-brain barrier (BBB) is noteworthy, facilitating the entry of peripheral immune cells and inflammatory molecules into the brain (111–115), thereby exacerbating neuroinflammation and neuronal damage in PD, as well as motor and cognitive impairment, and an increased risk of dementia in PD patients (107, 108, 116, 117). The gene discussed is IL6; the disease is Parkinson disease.