Aristolochic acids are a family of carcinogenic, mutagenic, and nephrotoxic compounds commonly found in the plant family Aristolochiaceae, including Aristolochia and Asarum (wild ginger), which are commonly used in Chinese herbal medicine. Aristolochic acid I is the most abundant of the aristolochic acids and is found in almost all Aristolochia species.Aristolochic acids are often accompanied by aristolactams. Aristolochic acids are hypothesized to be causative agents in Balkan endemic nephropathy; and a related—possibly identical—condition. Exposure to aristolochic acid is associated with a high incidence of uroepithelial tumorigenesis, and is linked to urothelial cancer. The agency warned that consumption of aristolochic acid-containing products was associated with "permanent kidney damage, sometimes resulting in kidney failure that has required kidney dialysis or kidney transplantation.