Especially drugs such as erythromycin and ketoconazole, which inhibit cytochrome P450 3A4 (Rendt, 2001), but also immunosuppressive drugs used to treat IBD can contribute to myositis, making it challenging to differentiate between myositis caused by EIM or drug-induced myositis (Zhou et al., 2015; Gaboriau et al., 2020; Yoshida et al., 2021; Jordan et al., 2022; Zengin et al., 2017; Chavarría-Miranda et al., 2021). The gene discussed is CYP3A4; the disease is myositis disease.