Zinc is an essential nutrient for all life, including plants, animals and microbes, because zinc is involved in many different cellular events. Zn2+ binds tightly to many proteins and thereby contributes to their tertiary structure or catalytic activity [1], and Zn2+ has been proposed to function as a second messenger signaling molecule during synaptic transmission, development, and immune responses. Zinc homeostasis is vital for human health.

Interleukin-6 (IL-6) is a pleiotropic cytokine with important functions in many physiological and pathophysiological conditions. IL-6 activates intracellular signaling cascades through a homodimer of the ubiquitously expressed β-receptor glycoprotein 130 (gp130) but first has to bind to its nonsignaling alpha receptor (IL-6R). The IL-6R is expressed in a cell- and tissue-specific manner and only found on hepatocytes and some leukocytes like neutrophils and T cells.