IGHE and asthma: A prospective cohort study by Perzanowski et al. examined 963 individuals aged 19 in Northern Sweden, investigating various cat allergens (Fel d 1, 2, 3, 4, 5) and dog allergens (Can f 1, 2, 3, 5) and their association with asthma symptoms, diagnosis, and treatment; they found that IgE to Fel d 1 is clinically related to current asthma.