However, further studies are needed todetermine whether CNTs, when administered in vivo in a clinical setting,could impact negatively on the metabolism of endogenous or xenobiotic compounds inthe liver; indeed, this deserves particular attention if CNTs are used to deliverdrugs that are either metabolized or bioactivated by the cytochrome P450 enzymes.CYP3A4, the CYP450 enzyme in focus here, is responsible for the biotransformation ofseveral important anti-cancer drugs, such as paclitaxel, doxorubicin, anddocetaxel45. The gene discussed is CYP3A4; the disease is cancer.