What is Pathology - What are cytokines and what do they do?

What is Pathology - What are cytokines and what do they do?
​Cytokines play a variety of roles, including mediating the following: 
- Activation of leukocytes, stimulating chemotaxis, phagocytosis, leukocyte adherence to endothelial cells, and recruitment of leukocytes to the site of inflammation 
-Endothelial cell responses, such as their anticoagulant or procoagulant activity 
- Increased erythrocyte sedimentation rate (ESR) in viral disorders is due to increased fibroblast and angioblast proliferation and production of granulation tissue, as well as fever and acute-phase reactant generation in the liver.