As rapid eye movement (REM) sleep behavior disorder (RBD) is not only an important symptom of prodromal PD but also a typical non-motor manifestations of PD (Berg et al., 2015; Schapira et al., 2017; Seppi et al., 2019), the diagnostic utility of plasma PGAM5 would be improved when combining with RBDQ-HK score. The gene discussed is PGAM5; the disease is Parkinson disease.