The encoded protein, which directly binds to pituitary tumor-transforming protein-1 (PTTG1), facilitates the nuclear translocation of PTTG1 and potentiates the transcriptional activation of basic fibroblast growth factor by PTTG1. The gene product localizes to both the cytoplasm and nucleus. Its NLS is required for its own nuclear localization, the nuclear localization of PTTG1, and its interaction with PTTG1.Synonyms: C21orf1, C21orf3, PBF, PTTG-binding factor, Pituitary tumor-transforming gene 1 protein-interacting protein, Pituitary tumor-transforming gene protein-binding factor