Peptidyl-prolyl cis-trans isomerase NIMA-interacting 1 (Pin1) is an isomerase enzyme that in humans is encoded by the PIN1 gene.

Pin1 isomerizes only phospho-Serine/Threonine-Proline motifs. The enzyme binds to a subset of proteins and thus plays a role as a post phosphorylation control in regulating protein function. Studies have shown that the deregulation