TNF and Parkinson disease: In addition, the development of inflammation in PD animals was accompanied by increased mRNA levels of Il1b (p < 0.01 in cortex and p < 0.001 in striatum, Figure 6), Il6, Tnf, Ptgs2 and Nfkb2 genes in cortex and striatum (p < 0.001 in all other cases) encoding IL-1β, IL-6, TNF-α precursor, cyclooxyhenase-2 (COX-2) and p100 precursor of NF-κB, respectively.