The role of IL-1β in PD pathogenesis may not be solely restricted to dopamine neuron loss and motor function, as lentiviral mediated overexpression of IL-1β in the hippocampus resulted in impaired cognitive function in rats [78] and elevated plasma levels of IL-1β have also been found in patients with mild cognitive impairment [79]. This evidence concerns the gene IL1B and Cognitive impairment.