FCER1
（重定向自Fc epsilon RI）
![The structure of the FcεRI receptor](/Images/godic/202501/12/FcεRI_Receptor1512.jpg")
![Summary of IgE/FcεRI receptor mediated downward signal cascade](/Images/godic/202501/12/IgE_FcεRI_Receptor_Signal_Cascade1513.jpg")
The high-affinity IgE receptor, also known as FcεRI, or Fc epsilon RI, is the high-affinity receptor for the Fc region of immunoglobulin E (IgE), an antibody isotype involved in the allergy disorder and parasites immunity. FcεRI is a tetrameric receptor complex consisting of one alpha (FcεRIα - antibody binding site), one beta (FcεRIβ - which amplifies the downstream signal), and two gamma chains (FcεRIγ - the site where the downstream signal initiates) connected by two disulfide bridges. It is constitutively expressed on mast cells and basophils and is inducible in eosinophils.