However, we found that blocking serotonin reuptake in Brunol4Ff/Ff homozygotes by fluoxetine (Prozac) treatment lowers the SWD incidence by about 50% (Figure 1E, right)—again suggesting that Htr2c down-regulation combines with other Brunol4-downstream deficiencies to cause the seizure disorder of frequent-flyer mutants. The gene discussed is CELF4; the disease is epilepsy.