English: Metabolic effects. IL-6 promotes GLUT4 translocation and glucose uptake in skeletal muscle, reduces visceral fat mass, increases lipolysis and glucose uptake in adipocytes, and stimulates GLP-1 secretion from intestinal L cells. Anti-inflammatory effects. IL-6 stimulates release of IL-10 and IL-1RA from macrophages and cortisol from adrenal glands, inhibits TNFα release from monocytes, reduces macrophage infiltration in adipose tissue, and promotes polarization of macrophages towards the anti-inflammatory M2 phenotype. Immunoregulatory effects. IL-6 contributes to the mobilisation of cytotoxic NK cells in humans and stimulates tumour infiltration of NK cells in mice, although exercise effects on NK cell tumour infiltration in humans is unclear. Direct effects. IL-6 directly inhibits cell proliferation and reduces DNA damage in early-stage colon cancer cells. Abbreviations: GLP-1, glucagon-like peptide 1; IGF, insulin-like growth factor 1; IGFBP-3, insulin-like growth factor binding protein 3; IL, interleukin; IL-1RA, IL-1 receptor antagonist; NK cell, natural killer cell; ROS, reactive oxygen species; SHBG, sex hormone binding globulin; TNFα, tumour necrosis factor α.