A study conducted in a cohort of White adults found that plasma mtDNA levels gradually increased after the age of 50 years; levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were positively associated with plasma mtDNA levels, suggesting a possible correlation between the level of blood mtDNA and age-associated mild chronic inflammation (92). Here, IL6 is linked to inflammatory response.