Tags: Protein.
Interleukins are a group of cytokines (secreted proteins and signaling molecules) that were first seen to be expressed by white blood cells (leukocytes).The function of the immune system depends in a large part on interleukins and rare deficiencies of a number of them have been described all featuring autoimmune diseases or immune deficiency. The majority of interleukins are synthesized by helper CD4 T lymphocytes as well as through monocytes macrophages and endothelial cells.