BRCA1 and hereditary breast ovarian cancer syndrome: A quantitative validation of these secreted metabolites in human samples showed that the plasma levels of adenine, N6-methyladenosine and 1-methylguanine could distinguish TN HBOC patients who were carriers of pathogenic BRCA1 mutations from TN HBOC patients who were non-carriers of BRCA mutations, supporting their putative role as BRCA1-like biomarkers in patients with HBOC syndrome and TNBC.