According to shreds of evidence, cytokines such as interleukin-1 β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α), are thought to play a key role in the occurrence and progression of PD, and measuring their levels in vivo is essential for making an early diagnosis of the disease. The gene discussed is IL6; the disease is Parkinson disease.