Cytokines are small secreted proteins released by cells have a specific effect on the interactions and communications between cells. The word cytokine is derived from the Greek kytos meaning ‘hollow’ or ‘vessel’ and kinein meaning ‘to move’ and was originally used to separate a group of immuno-regulatory proteins, such as interleukins, from other chemicals, known as growth factors, that modulated the proliferation and bioactivation of nonimmune cells.

1. What are cytokines?
Cytokines are small secreted proteins released by cells have a specific effect on the
interactions and communications between cells. The word cytokine is derived from
the Greek kytos meaning ‘hollow’ or ‘vessel’ and kinein meaning ‘to move’ and was
originally used to separate a group of immuno-regulatory proteins, such as
interleukins, from other chemicals, known as growth factors, that modulated the
proliferation and bioactivation of nonimmune cells. Cytokines aid cell to cell
communication in immune responses and stimulate the movement of cells towards
sites of inflammation, infection and trauma.
Most cytokines names are given based on cell types, biological activity and the
structure. The term ‘cytokine’ was first introduced in the mid-1970s. It was applied to
polypeptide growth factors controlling the differentiation and regulation of cells of
the immune system. The interferons (IFNs) and interleukins (ILs) represented the
major polypeptide families classified as cytokines at that time.
Interferons (IFNs) – Interferons (IFNs) are a group of signaling proteins made and
released by host cells in response to the presence of several pathogens, such as
viruses, bacteria, parasites, and also tumor cells.
http://www.creative-diagnostics.com/blog/index.php/what-are-cytokines/