CYP3A5*3 genetic polymorphism is widely regarded as an essential factor to the high individual variability of TAC (Woillard et al., 2017; Brunet et al., 2019; Mendrinou et al., 2020; van Gelder et al., 2020), and pediatric PNS patients with the CYP3A5*1 allele (rapid metabolizer) have lower TAC exposure than those who do not express CYP3A5 (CYP3A5*3/*3, slow metabolizer) (Huang et al., 2019). Here, CYP3A5 is linked to paraneoplastic neurologic syndrome.