IL6 and chronic kidney disease: The serum levels of interleukin (IL) 1β (17.5 kDa), IL-6 (21.0–28.0 kDa), and IL-18 (18.0 kDa) as well as κ (22.5 kDa) and λ (45.0 kDa) free light chains (FLCs) are also elevated in patients with advanced chronic kidney disease (CKD) [2].