The BRCA-1 gene codes for a nuclear phosphoprotein that plays a role in maintaining genomic stability and acts as a tumor suppressor. Mutations of BRCA1 genes have been linked to an increased risk of developing breast and ovarian cancers. Individuals with certain mutations in BRCA1 may have a higher likelihood of developing these cancers compared to those without the mutations. BRCA1 immunohistochemistry is commonly used in research and clinical settings. It can provide valuable information about the status of the BRCA1 protein in cancerous and non-cancerous tissues. Changes in BRCA1 expression can be associated with certain types of breast and ovarian cancers, and this information may be used in the diagnosis, prognosis, and treatment planning for patients.