The Fc Fragment of IgE Receptor II (FCER2) is expressed in several cells, such as macrophages, eosinophils, B cells and platelets. Studies have suggested that FCER2 is involved in the regulation of IgE responses, growth and differentiation of T and B cells, cellular adherence and antigen presentation. The activation of the receptor results in down-regulation of IgE-mediated immune responses. Two studies found that individuals with asthma on inhaled corticosteroids (ICS) with the CC genotype of the rs28364072 polymorphism had a two-fold increased odds of asthma exacerbations and uncontrolled asthma than individuals with at least one copy of the T allele (CT/TT).