The use of biomarkers as prognostic and predictive indicators of treatment efficacy is an important application for clinical research. A new study of patients suffering from late-stage kidney cancer examined the link between the levels of lactate dehydrogenase (LDH) and the response to mTOR inhibitors, a group of drugs that targets a specific cancer gene pathway. LDH is a known cancer biomarker and has previously been shown to be elevated in aggressive kidney cancer. Researchers at the Duke University Medical Center found that patients with high serum levels of LDH responded better to mTOR inhibitors than interferon-alpha treatment as measured by survival benefit. Doctors are hopeful that these findings can be extrapolated to other cancer types.