– Peptidyl-prolyl cis-trans isomerase FKBP2(FKBP2 for short), also named 13 kDa FK506-binding protein, FK506-binding protein 2, Immunophilin FKBP13, Rotamase, is a endoplasmic reticulum peripheral membrane protein. It contains 1 PPIase FKBP-type domain and belongs to the FKBP-type PPIase family, FKBP2 subfamily which takes part in immunoregulation and basic cellular processes involving protein folding and trafficking. FKBP2 is a cis-trans prolyl isomerase that binds the immunosuppressants FK506 and rapamycin. FKBP2 functions as an ER chaperone and as a component of membrane cytoskeletal scaffolds.