IL6 and COVID-19: Particularly, the IL-6 levels observed in acute infections (e.g., COVID-19 patients) could reach approximately 70 pg/ml [34], while the aging-associated elevation of IL-6 is mild (e.g., ~ 3.5 pg/ml for men and ~ 2.1 pg/ml for women aged ≥ 85 years old) [35].