As the allergen enters through the nose or mouth, antigen cells analyze the allergen and present antigenic peptides to helper T cells.[1] The helper T cells acquire a type 2 phenotype (Th2) and produce IgE due the presence of specific cytokines. If Th2 is expressed too much, the symptoms of cat allergies appear. Inhaled cat allergens will activate mast cells, causing coughing, increased mucous production, and airway constriction.