The FKBP5 gene encodes FKBP prolyl isomerase 5, a co-chaperone that modulates glucocorticoid signaling and that is expressed in T cells, neurons and in microglial cells in the central nervous system (CNS). The role of FKBP5 in the dysregulation of myeloid cells in the pathogenesis of multiple sclerosis was investigated in a murine model of experimental autoimmune encephalomyelitis.