TNF and Parkinson disease: Inflammation is implicated in the pathogenesis of PD (Liu et al., 2003; Herrero et al., 2015; Ransohoff, 2016) increases in innate immune components such as interleukin (IL)-1β, IL-6 and TNF-α have been detected in the cerebrospinal fluid and SN of PD patients (Fiszer et al., 1994; Liu et al., 2003).