In 2019, Seo et al investigated AD phenotypes in children <3 years of age and classified AD into four subgroups: “early-onset, non-allergic AD”, “early-onset AD with high eosinophil and food sensitization”, “early-onset AD with high C-reactive protein”, and “middle-onset AD with inhalant sensitization”.4 The gene discussed is CRP; the disease is Alzheimer disease.