In our DS cohort, more than 25% subjects were carrying heterozygous ApoE ɛ4 allele and interestingly all such subjects had higher serum IL-6 levels (average 465.85 pg/ml) compared to the DS subjects carrying ApoE ε2/ε3 allele (average 129.93 pg/ml; Henderson et al., manuscript is in progress). This evidence concerns the gene IL6 and Dravet syndrome.