Which recent discovery led to a new understanding of how genetic mutations increase the risk of cancer? double helix structure of dnabrca1 and brca2 genesnucleic acid monomerschemical composition of proteins

Double helix structure of dna brca1 and brca2. BRCA1 expression is reduced or undetectable in the majority of high grade, ductal breast cancers. It has long been noted that loss of BRCA1 activity, either by germ-line mutations or by down-regulation of gene expression, leads to tumor formation in specific target tissues. In particular, decreased BRCA1 expression contributes to both sporadic and inherited breast tumor progression.