For patients with CYP genetic variations, remdesivir is generally a safer choice since its activation depends on CES rather than CYP, but for patients who receive remdesivir as a COVID-19 treatment, there is a risk of drug-drug interactions with other medications metabolized by CES2 since remdesivir has been shown to inhibit CES2 [35]. The gene discussed is CES2; the disease is COVID-19.