In fact, although increased IgE-mediated reactivity to food proteins has been found in many patients with allergic diseases such as AD [17,21,22,23,24,25], according to some authors, their relationship should be interpreted in a multimorbidity framework, thus their co-occurrence does not imply any specific relationship between them and certainly not a progressive or causal relationship, thus questioning the legitimacy of the atopic march model [1,17,21,22,23,24,25]. The gene discussed is IGHE; the disease is Alzheimer disease.