CYP2D6 and tuberculosis: Regarding the CYP2D subfamily, CYP2D6 not only increases the risk of liver damage from anti-tuberculosis drugs in Chinese populations (Hu et al., 2018; Wei et al., 2020), but also causes excessive accumulation of tramadol bioactive metabolites, which can increase oxidative stress and cause liver toxicity (Qin et al., 2009; Arafa and Atteia, 2018).