CSU is a mast cell‐mediated disease, and its underlying mechanism is based on autoimmunity, driven by two distinct pathways of mast cell activation: the Type IIb autoimmune endotype (caused by IgG‐type autoantibodies against the FcER1 and IgE) and the Type I autoallergic endotype (caused by IgE‐type autoantibodies against self‐antigens such as thyroid peroxidase).4 The gene discussed is IGHE; the disease is Autoimmunity.