IGHE and allergic disease: Given their importance, many lipocalins of domestic animals and pets have been cloned and their production improved (such as Can f 1, ‐2, or ‐4 37, 38, 39, 40), but methods were also developed for the quantification of the natural allergens to be able to evaluate the exposure levels in different environments, e.g., for Can f 4 41 which is important for over 80% of people with dog allergies for IgE binding.