PPIL2 is part of the cyclophilin family of peptidylprolyl isomerases which are highly conserved ubiquitous proteins that play an important role in protein folding, immunosuppression by cyclosporin A, and infection of HIV-1 virions. PPIL2 interacts with the proteinase inhibitor eglin c and is localized in the nucleus. PPIL2 increases folding of proteins andcatalyzes the cis-trans isomerization of proline imidic peptide bonds in oligopeptides.