In humans, the leading cause of cancer deaths worldwide is lung cancer, including non small cell lung carcinoma (NSCLC) which accounts for 85% of all lung cancer cases in the United States. Individuals with NSCLC are often treated with therapeutic platinum compounds (e.g. cisplatin, carboplatin or oxaliplatin) (see Lung cancer chemotherapy) that cause interstrand DNA crosslinks. Among individuals with NSLC, low expression of the breast cancer 1 gene ("BRCA1)" in the primary tumor has correlated with improved survival after platinum-containing chemotherapy. This correlation implies that low BRCA1 in the cancer, and the consequent low level of DNA repair, causes vulnerability of the cancer to treatment by the DNA crosslinking agents. High BRCA1 may protect cancer cells by acting in the homologous recombinational repair pathway that removes the damages in DNA introduced by the platinum drugs. The level of "BRCA1" expression is potentially an important tool for tailoring chemotherapy in lung cancer management.