Cyclophilins facilitate the process of protein folding. They catalyzes the cis-trans isomerization of proline imidic peptide bonds. Cyclophilin F is located in mitochondrion matrix. Cyclophilin F is involved in regulation of the mitochondrial permeability transition pore. It may activate or inhibit apoptosis or necrosis. It binds to an immunosuppressant cyclosporin.