The effects of genes, for example, ABCB1 (ATP-binding cassette subfamily B member 1, a drug transporter) [9], on epilepsy and interactions of HLA-A (major histocompatibility complex, class I, A) with adverse AED events [10] were investigated, highlighting the critical roles of genetic variation and heterogeneity in epilepsy treatment. This evidence concerns the gene ABCB1 and epilepsy.