The most significant differences were found in patients with focal seizures in the polymorphism analysis of SNP rs2242480 in CYP3A4. The prevalence of CT+TT genotypes was 64% for those without response to CBD treatment (CBDneg), while the prevalence was 33% for patients with a CBD treatment response (CBDpos), resulting in a difference of 31%. This evidence concerns the gene CYP3A4 and red-green color blindness.