While cytokines is an umbrella term that includes all kinds, there are more specific names given to cytokines. The major proteins/protein families that constitute the cytokine group of regulatory molecules.

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.

Interleukins (ILs) - Interleukins are a group of cytokines that were first seen to be expressed by leukocytes and acting on other leukocytes.