SAFB is a DNA-binding protein which has high specificity for scaffold or matrix attachment region DNA elements (S/MAR DNA). SAFB plays a crucial role in nuclear matrix organization and regulates gene expression by binding to matrix- or scaffold-associating regions (MARs or SARs) on DNA. This interaction facilitates RNA polymerase II recruitment and serine-/arginine-rich RNA processing factors, essential for pre-mRNA processing and transport. SAFB interacts with estrogen receptor, suggesting involvement in breast cancer biology, where SAFB may influence cellular proliferation and division. SAFB exhibits a speckled distribution in the nucleus under normal conditions but can be recruited to larger nuclear granules, known as perichromatin granules, in response to stressors such as heat shock.