CYP2C9 and epilepsy: Approximately 526 genes associated with epilepsy have been listed in the PHGKB—for instance, SCN1A (sodium voltage-gated channel alpha subunit 1) as a drug target gene [40,41,42] and CYP2C9 (cytochrome P450 family 2 subfamily C member 9), which is involved in drug metabolism [43,44], have been examined in epilepsy studies.