In addition, melanoma CSCs may be identified by the expression of specific stemness biomarkers, such as surface markers associated with melanocyte undifferentiated state or with drug resistance (ATP-binding cassette transporters involved in drug efflux out of the cells) and intracellular markers involved in drug metabolism (i.e., those belonging to the aldehyde dehydrogenase -ALDH- family). The gene discussed is LDHA; the disease is melanoma.