Fel d 1 is the most prominent cat allergen, accounting for 96% of human cat allergies.[2] The remaining cat allergens are Fel d 2–8,[3] with Fel d 4, an urinary protein, occurring the most in humans among the other seven allergens. All cats produce Fel d 1 including hypoallergenic cats. The main way these allergens are spread is through a cat's saliva or dander, which gets stuck on clothing.