CYP2D6 is a very important pharmacogene that is highly polymorphic and responsible for metabolism of up to 25% of medicines, including many psychotropic drugs which are also used for the treatment of motion-sickness (for reference of the CYP2D6 psychotropic substrates and pharmacogenetic variability, see Stingl Mol Psychiatry 2013) (Owen et al., 2009; Stingl et al., 2013). The gene discussed is CYP2D6; the disease is motion sickness.