CD4 and autoimmune disease: Chemical inhibition of cyclin-dependent kinases (CDK) 8/19, which reversibly associate with the Mediator complex and control transcription positively and negatively, is able to induce FoxP3 in antigen-stimulated effector/memory as well as naïve CD4+ and CD8+ T cells in vitro.117 Furthermore, in vivo administration of a CDK8/19 inhibitor along with antigen immunization is able to generate functionally stable (i.e., epigenetically in Treg-type) antigen-specific FoxP3+ Treg cells, which effectively suppress autoimmune disease in animal models.