IL6 and Cognitive impairment: Overall, these studies demonstrated that those children presented early markers of neurodegeneration, neuroinflammation (e.g., elevated macrophage inhibitory factor (MIF), IL-6, and IL-2 in CSF [69] and increased IL-6 and Toll-like receptors (TLRs) expression in frontal cortex), olfactory dysfunction, and cognitive deficits compared to control children from nearby non-polluted cities.