FKBPL, also named as DIR1, NG7 and WISp39, has similarity to the immunophilin protein family, which plays a role in immunoregulation and basic cellular processes involving protein folding and trafficking. This protein is thought to have a potential role in the induced radioresistance, probably by increasing the rate of DNA repair in cells exposed to X rays. Also it appears to have some involvement in general stress response in the control of the cell cycle. It regulates p21 protein stability by binding to Hsp90 and p21. Breast cancer cells stably overexpressing FKBPL became dependent on estrogen for their growth and were dramatically more sensitive to the antiestrogens tamoxifen and fulvestrant, whereas FKBPL knockdown reverses this phenotype. FKBPL is an estrogen-inducible gene that acts as a cochaperone in ERα/Hsp90 molecular complexes; furthermore, FKBPL levels may be both a prognostic indicator and determinant of response to endocrine therapy. (PMID:20103631, 15664193) This antibody is specific to FKBPL.