5-Fluoroorotic acid is a fluorinated derivative of the pyrimidine precursor orotic acid. 5-Fluoroorotic acid exert considerable antitumor activity against transplanted tumors in rats and mice. 5-Fluoroorotate shows increased cytotoxicity on ovarian carcinoma cell lines following encapsulation in liposomes. 5-Fluoroorotic acid is used in vitro in the positive selection of genetically transformed yeast cells.

Aristolochic acid (AA-I), a naturally occurring nitrophenanthrene carboxylic acid, commonly found in the plant family Aristolochiaceae, that are used in traditional Chinese medicine. Aristolochic acid exhibits nephrotoxic, carcinogenic, and mutagenic activities and can cause aristolochic acid nephropathy, and urothelial malignancies. The FDA has issued a strong warning to consumers to avoid herbs containing the chemical aristolochic acid. The mechanisms underlying AA-I toxicity in the kidneys are poorly understood. However, was found a protein α-actinin-4 that is inhibited by AA-I, resulting in kidney disease.