Test Catalog

Test ID: INI1    
Integrase Interactor 1 (INI1/BAF47) Immunostain, Technical Component Only

Useful For Suggests clinical disorders or settings where the test may be helpful

Part of a panel of immunostains where loss of staining can be used as a marker of various neoplasms

Testing Algorithm Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

For the initial technical component only immunohistochemical (IHC) stain performed, the appropriate bill-only test ID will be reflexed and charged (IHTOI). For each additional technical component only IHC stain performed, an additional bill-only test ID will be reflexed and charged (IHTOA).

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Integrase interactor 1 (INI1) is a member of the SWI/SNF (SWItch/sucrose non-fermentable) chromatin remodeling complex. They play an important role in regulation of transcription by modulating access of protein to DNA. Loss of function of these complexes has been implicated in human cancers. Point alterations and deletions of the INI BAF47 gene may be seen in pediatric rhabdoid tumors, rhabdomyosarcoma, chronic myeloid leukemia, and in central nervous system (CNS) tumors (medulloblastomas and choroid plexus carcinomas) where loss of nuclear staining for INI1/BAF47 is seen. In normal tissues, nuclear expression of INI1/BAF4 should be present in all cell types.

Interpretation Provides information to assist in interpretation of the test results

This test does not include pathologist interpretation, only technical performance of the stain. If interpretation is required, order PATHC / Pathology Consultation for a full diagnostic evaluation or second opinion of the case.


The positive and negative controls are verified as showing appropriate immunoreactivity and documentation is retained at Mayo Clinic Rochester. If a control tissue is not included on the slide, a scanned image of the relevant quality control tissue is available upon request; call 855-516-8404.


Interpretation of this test should be performed in the context of the patient's clinical history and other diagnostic tests by a qualified pathologist.

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

Age of a cut paraffin section can affect immunoreactivity. Stability thresholds vary widely among published literature and are antigen dependent. Best practice is for paraffin sections to be cut within 6 weeks.

Clinical Reference Recommendations for in-depth reading of a clinical nature

1. Judkins AR, Mauger J, Ht A, Rorke LB, Biegel JA: Immunohistochemical analysis of hSNF5/INI1 in pediatric CNS neoplasms. Am J Surg Pathol. 2004;28(5):644-650. doi: 10.1097/00000478-200405000-00013
2. DeCristofaro MF, Betz BL, Rorie CJ, Reisman DN, Wang W, Weissman BE: Characterization of SWI/SNF protein expression in human breast cancer cell lines and other malignancies. J Cell Physiol. 2001;186:136-145. doi: 10.1002/1097-4652(200101)186:1<136::AID-JCP1010>3.0.CO;2-4
3. Kleinschmidt-DeMaster BK, Meltesen L, McGavran L, Lillehei KO: Characterization of glioblastomas in young adults. Brain Pathol. 2006;16:273-286. doi: 10.1111/j.1750-3639.2006.00029.x

4. Parham DM: Immunohistochemical markers of soft tissue tumors: pathologic diagnosis, genetic contributions, and therapeutic options. Anal Chem Insights. 2015 Oct 29;10(Suppl 1):1-10. doi: 10.4137/ACI.S32730