Mx proteins are cytoplasmic proteins induced by type-1 interferons (α and β) in leukocytes. However, there is a baseline level of expression even in the absence of viral infection. In humans, mainly monocytes and lymphocytes have been shown to express the Mx gene, whereas Mx expression is low in granulocytes. Mx proteins are high molecular weight GTPases of 70 - 80kD which belong to the dynamin superfamily. Mx proteins have a strong propensity to aggregate and form homooligomers. A unique property is their antiviral activity against many RNA viruses.Synonyms: Mx1 protein