BLM(Bloom syndrome) is an autosomal recessive disorder characterized by growth deficiency, microcephaly and immunodeficiency among others. BLM plays a crucial role in maintaining genomic stability by unwinding DNA during replication and repair processes, which is vital for preventing mutations that can lead to cancer. BLM is primarily located in the nucleus, where BLM interacts with both single- and double-stranded DNA, and BLM′s ATPase activity is essential for its helicase function. Mutations in the BLM gene result in Bloom′s syndrome, characterized by an increased frequency of sister chromatid exchange, which is a hallmark of genomic instability. This instability is linked to a higher predisposition to various cancers, making BLM a significant focus of research in cancer biology and genetics.