<p> Macrophage migration inhibitory factor (MIF) is a key regulatory cytokine within innate and adaptive immune responses, capable of promoting and modulating the magnitude of the response [<cite idref="PUB00034437"/>]. MIF is released from T-cells and macrophages, and acts within the neuroendocrine system. MIF is capable of tautomerase activity, although its biological function has not been fully characterised. It is induced by glucocorticoid and is capable of overriding the anti-inflammatory actions of glucocorticoid [<cite idref="PUB00034438"/>]. MIF regulates cytokine secretion and the expression of receptors involved in the immune response. It can be taken up into target cells in order to interact with intracellular signalling molecules, inhibiting p53 function, and/or activating components of the mitogen-activated protein kinase and Jun-activation domain-binding protein-1 (Jab-1) [<cite idref="PUB00034437"/>]. MIF has been linked to various inflammatory diseases, such as rheumatoid arthritis and atherosclerosis [<cite idref="PUB00034439"/>].</p><p>The MIF homologue D-dopachrome tautomerase (<db_xref db="EC" dbkey="4.1.1.84"/>) is involved in detoxification through the conversion of dopaminechrome (and possibly norepinephrinechrome), the toxic quinine product of the neurotransmitter dopamine (and norepinephrine), to an indole derivative that can serve as a precursor to neuromelanin [<cite idref="PUB00034440"/>, <cite idref="PUB00024290"/>].</p><p>The signature pattern for this entry is formed from a conserved region located in the central section. </p>