Abstract
Breast cancer (BC) remains one of the most prevalent cancers worldwide and a significant cause of cancer-related mortality among women. Despite significant advancements in understanding the genetic foundations of BC, numerous research initiatives have historically focused on protein-coding genes, which constitute merely about 2% of the human genome. This focus has produced significant insights into oncogenes such as HER2, TP53, and BRCA1, along with tumor suppressor genes. Nonetheless, it has led to the non-coding portions of the genome garnering relatively less focus. Recent studies illuminate the crucial significance of non-coding DNA in cancer biology, highlighting its regulatory roles and influence on tumor formation, metastasis, and treatment resistance. This review examines the importance of non-coding DNA in BC. It provides an in-depth analysis of essential non-coding regions, their functions in gene regulation and chromatin structure, and their implications for various BC subtypes. Examining these facets, we seek to reveal the potential of non-coding DNA as a viable source of novel diagnostic markers and treatment approaches.