As seen in Figure 2, a ranking based on the quality of the diagnosis of the food allergies and on the characteristics of the patient populations used in the studies was carried out for the Population-Outcome approach, while the methods used to assess IgE binding, and the quality of allergen preparations were graded for the Population-Exposure-Comparison-Outcome (Mills et al., 2024). This evidence concerns the gene IGHE and food allergy.