IL4 and Parkinson disease: In previous studies, it was shown that the cerebrospinal fluid (CSF) and nigrostriatal DA areas in PD patients had significantly higher amounts of cytokines, such TNF-α, interleukin-1 (IL-1), interleukin-2 (IL-2), interleukin-4 (IL-4), and interleukin-6 (IL-6) [4].