is known to have a polymorphism that is associated with increased amounts of CD14 protein as well as reduced levels of IgE serum. A study was conducted on 624 children looking at their IgE serum levels as it related to the polymorphism in CD14. The study found that IgE serum levels differed in children with the C allele in the CD14/-260 gene based on the type of allergens they regularly exposed to. Children who were in regular contact with house pets showed higher serum levels of IgE while children who were regularly exposed to stable animals showed lower serum levels of IgE. Continued research into gene-environment interactions may lead to more specialized treatment plans based on an individual's surroundings. References Genes Polymorphism (biology)