Another environmental carcinogen which has been tested in HCT116 TP53(+/+) and TP53(−/−) cells is aristolochic acid I (AAI), a herbal drug derived from the Aristolochia species which is a potent human carcinogen involved in the development of aristolochic acid nephropathy and linked to urothelial cancer (Gokmen et al. 2013; Schmeiser et al. 2014). This evidence concerns the gene TP53 and Balkan nephropathy.