Cytokines are soluble protiens/polypeptides, produces by a variety of hematopoetic and non hematopoetic cell types. They are responsible for the regulation of immunological, inflammatory and reparative host responses.

Cytokines tend to bind to high affinity receptors and the target cells and mediate their effects. Specific cytokines mediate specific reactions.

Cytokines basically mediate immune response. But some cytokines are also pro inflammatory.
These are:-
Il-1, TNF alpha and IL-6.
IL-1 is the most important pro inflammatory cytokine.
Anti inflammatory cytokines are involved in the resolution of inflammation. These include:
IL-4, IL-10 IL-13 and TGF beta.
IL-4 has mainly anti-inflammatory properties with some pro-inflammatory properties.
TGF-beta is the most important fibrogenic factor.