The analysis showed that there was a statistically significant correlation of CSF cell-free mtDNA with IL-6 (r = 0.307, p = 0.041), but neither with IL-10 (r = −0.085, p = 0.319) nor TNF-α (r = −0.050, p = 0.391) in the acute stage of anti-NMDAR encephalitis. This evidence concerns the gene IL6 and viral encephalitis.